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A-01 | Explore EOS

Overview

In this lab, you'll learn how to log into an Arista switch and explore configuration. All Arista switches, whether they’re used in data center, campus, WAN, or other environments, run on Arista's Extensible Operating System (EOS). We’ll also cover MLAG, how to configure it, and how to troubleshoot issues!

Let’s take a closer look at the EOS interface—while it might feel familiar, it’s also distinctly unique!

Completely Different, Totally Familiar

Let's log into the workshop spine switches.

I have a console cable or WiFi

If you have a console cable, feel free to console into your switch. The switch is in ZTP, you can explore the same commands! You may also use the WiFi to connect to the spine switches. The spine switch is running configuration your switch will not contain, but login using admin, hit Enter and type in enable to start exploring

  1. Login to the spine using the address below and the username student#, password Arista123.

    # Student 1
ssh student1@10.1.100.2

# Student 2
ssh student2@10.1.100.3

  2. First thing, let's validate you are on the spine switch and explore the hardware.

    show version
    Example Output
    Example Output
    Arista CCS-720XP-24ZY4-F
Hardware version: 11.22
Serial number: HBG232901HT
Hardware MAC address: fc59.c0ff.0e17
System MAC address: fc59.c0ff.0e17

Software image version: 4.34.0F
Architecture: i686
Internal build version: 4.34.0F-41661064.4340F
Internal build ID: 8346ed5e-061a-4a70-9c36-b6eee6fc0848
Image format version: 3.0
Image optimization: Strata-4GB

Uptime: 2 days, 2 hours and 39 minutes
Total memory: 3952928 kB
Free memory: 2029952 kB
    1. The full switch model
    2. The serial number of the switch
    3. Current EOS image running
    4. This EOS software is a 32-bit version, Arista EOS is also provided in a 64-bit version
    5. The current uptime

  3. Let's explore the hardware in a bit more detail. Text output is great, but imagine you have been asked to pull all device information programmatically. Tools like TextFSM are common to parse unstructured data, wouldn't it be great if this data was structured? Try validating this command will also render as json.

    show inventory
show inventory | json
    Example Output
Example Output
        System information
  Model                    Description                                         
  ------------------------ ----------------------------------------------------
  CCS-720XP-24ZY4          24 MGig Base-T PoE & 4-port SFP28 Switch            

  HW Version  Serial Number  Mfg Date   Epoch
  ----------- -------------- ---------- -----
  11.22       HBG232901HT    2023-07-26 01.00

System has 2 power supply slots
  Slot Model            Serial Number   
  ---- ---------------- ----------------
  1    PWR-621-AC-RED   FFKT96307BE     
  2    PWR-621-AC-RED   FFKT96307CT     

System has 3 fan modules
  Module  Number of Fans  Model            Serial Number   
  ------- --------------- ---------------- ----------------
  1       1               FAN-7000-F       N/A             
  2       1               FAN-7000-F       N/A             
  3       1               FAN-7000-F       N/A             

System has 29 ports
  Type               Count
  ------------------ ----
  Management         1   
  Switched           24  
  SwitchedBootstrap  4   

System has 28 switched transceiver slots
  Port Manufacturer     Model            Serial Number    Rev 
  ---- ---------------- ---------------- ---------------- ----
  1    Arista Networks  CCS-720XP-24ZY4                       
  2    Arista Networks  CCS-720XP-24ZY4                       
  3    Arista Networks  CCS-720XP-24ZY4                       
  4    Arista Networks  CCS-720XP-24ZY4                       
  5    Arista Networks  CCS-720XP-24ZY4                       
  6    Arista Networks  CCS-720XP-24ZY4                       
  7    Arista Networks  CCS-720XP-24ZY4                       
  8    Arista Networks  CCS-720XP-24ZY4                       
  9    Arista Networks  CCS-720XP-24ZY4                       
  10   Arista Networks  CCS-720XP-24ZY4                       
  11   Arista Networks  CCS-720XP-24ZY4                       
  12   Arista Networks  CCS-720XP-24ZY4                       
  13   Arista Networks  CCS-720XP-24ZY4                       
  14   Arista Networks  CCS-720XP-24ZY4                       
  15   Arista Networks  CCS-720XP-24ZY4                       
  16   Arista Networks  CCS-720XP-24ZY4                       
  17   Arista Networks  CCS-720XP-24ZY4                       
  18   Arista Networks  CCS-720XP-24ZY4                       
  19   Arista Networks  CCS-720XP-24ZY4                       
  20   Arista Networks  CCS-720XP-24ZY4                       
  21   Arista Networks  CCS-720XP-24ZY4                       
  22   Arista Networks  CCS-720XP-24ZY4                       
  23   Arista Networks  CCS-720XP-24ZY4                       
  24   Arista Networks  CCS-720XP-24ZY4                       
  25   MergeOptics GmbH 10119467-2010LF  CN81KBZ01C       F   
  26   Arista Networks  CAB-S-S-25G-1M   XPK221730456     20  
  27   Not Present                                            
  28   Not Present                                            

System has 1 storage device
  Mount      Type Model                Serial Number Rev Size (GB)
  ---------- ---- -------------------- ------------- --- ---------
  /mnt/flash eMMC Smart Modular 08GP1A 80199f4c      1.0 8        

    1. More information about this switch platform capabilities
    2. You can see when this switch was manufactured and hardware versioning
    3. Power supply details, like model and serial number
    4. If you have fan modules, similar detail to that of power supplies
    5. Get optics manufacturer, serial number, and model

  1. Let's explore the interfaces and what's connected. Take note

    1. Your pod has one connection to the spine (we're not in a full mesh)
    2. Workshop access point and raspberry pi (lab guides) are connected
    3. MLAG interfaces
    4. Your POD is configured as part of a Port-Channel
    show interfaces status
    Example Output
    Example Output
    Port       Name                               Status       Vlan     Duplex Speed  Type         Flags Encapsulation
 Et1        POD01-LEAF1A                       notconnect   trunk    auto   auto   2.5GBASE-T                     
 Et2        POD02-LEAF1A                       notconnect   trunk    auto   auto   2.5GBASE-T                     
 Et3        POD03-LEAF1A                       notconnect   trunk    auto   auto   2.5GBASE-T                     
 Et4        POD04-LEAF1A                       notconnect   trunk    auto   auto   2.5GBASE-T                     
 Et5        POD05-LEAF1A                       connected    in Po105 a-full a-1G   2.5GBASE-T                     
 Et6        POD06-LEAF1A                       connected    in Po106 a-full a-1G   2.5GBASE-T                     
 Et7        POD07-LEAF1A                       notconnect   trunk    auto   auto   2.5GBASE-T                     
 Et8        POD08-LEAF1A                       notconnect   trunk    auto   auto   2.5GBASE-T                     
 Et9        POD09-LEAF1A                       notconnect   trunk    auto   auto   2.5GBASE-T                     
 Et10       POD10-LEAF1A                       notconnect   trunk    auto   auto   2.5GBASE-T                     
 Et11       POD11-LEAF1A                       notconnect   trunk    auto   auto   2.5GBASE-T                     
 Et12       POD12-LEAF1A                       notconnect   trunk    auto   auto   2.5GBASE-T                     
 Et13       POD13-LEAF1A                       notconnect   trunk    auto   auto   2.5GBASE-T                     
 Et14       POD014LEAF1A                       notconnect   trunk    auto   auto   2.5GBASE-T                     
 Et15       POD015-LEAF1A                      notconnect   trunk    auto   auto   2.5GBASE-T                     
 Et16       POD16-LEAF1A                       notconnect   trunk    auto   auto   2.5GBASE-T                     
 Et17       POD17-LEAF1A                       notconnect   trunk    auto   auto   5GBASE-T                       
 Et18       POD18-LEAF1A                       notconnect   trunk    auto   auto   5GBASE-T                       
 Et19       POD19-LEAF1A                       notconnect   trunk    auto   auto   5GBASE-T                       
 Et20       POD20-LEAF1A                       notconnect   trunk    auto   auto   5GBASE-T                       
 Et21       POD00-LEAF1A                       notconnect   trunk    auto   auto   5GBASE-T                       
 Et22       AP C-330 LAN1                      notconnect   trunk    auto   auto   5GBASE-T                       
 Et23       Trunk Group to NAT inside networks connected    trunk    a-full a-1G   5GBASE-T                       
 Et24       RasPi5                             notconnect   100      auto   auto   5GBASE-T                       
 Et25       MLAG_spine2_Ethernet25             connected    in Po25  full   10G    10GBASE-CR                     
 Et26       MLAG_spine2_Ethernet26             connected    in Po25  full   25G    25GBASE-CR                     
 Et27                                          notconnect   1        full   25G    Not Present                    
 Et28                                          notconnect   1        full   25G    Not Present                    
 Ma1                                           disabled     routed   unconf unconf 10/100/1000                    
 Po1        JS-LEAFA_Po10                      notconnect   trunk    full   unconf N/A                            
 Po2        POD02-LEAF1A_Po10                  notconnect   trunk    full   unconf N/A                            
 Po3        POD03-LEAF1A_Po10                  notconnect   trunk    full   unconf N/A                            
 Po7        SW-10.1.7.42_Po10                  notconnect   trunk    full   unconf N/A                            
 Po18                                          notconnect   1        full   unconf N/A                            
 Po25       MLAG_PEER_spine2_Po25              connected    trunk    full   25G    N/A                            
 Po100      POD00-LEAF1A                       notconnect   trunk    full   unconf N/A                            
 Po101      POD01-LEAF1A                       notconnect   trunk    full   unconf N/A                            
 Po102      POD02-LEAF1A                       notconnect   trunk    full   unconf N/A                            
 Po103      POD03-LEAF1A                       notconnect   trunk    full   unconf N/A                            
 Po104      POD04-LEAF1A                       notconnect   trunk    full   unconf N/A                            
 Po105      POD05-LEAF1A                       connected    trunk    full   2G     N/A                            
 Po106      POD06-LEAF1A                       connected    trunk    full   2G     N/A                            
 Po107      POD07-LEAF1A                       notconnect   trunk    full   unconf N/A                            
 Po108      POD08-LEAF1A                       notconnect   trunk    full   unconf N/A                            
 Po109      POD09-LEAF1A                       notconnect   trunk    full   unconf N/A                            
 Po110      POD10-LEAF1A                       notconnect   trunk    full   unconf N/A                            
 Po111      POD11-LEAF1A                       notconnect   trunk    full   unconf N/A                            
 Po112      POD12-LEAF1A                       notconnect   trunk    full   unconf N/A                            
 Po113      POD13-LEAF1A                       notconnect   trunk    full   unconf N/A                            
 Po114      POD014LEAF1A                       notconnect   trunk    full   unconf N/A                            
 Po115      POD015-LEAF1A                      notconnect   trunk    full   unconf N/A                            
 Po116      POD16-LEAF1A                       notconnect   trunk    full   unconf N/A                            
 Po117      POD17-LEAF1A                       notconnect   trunk    full   unconf N/A                            
 Po118      POD18-LEAF1A                       notconnect   trunk    full   unconf N/A                            
 Po119      POD19-LEAF1A                       notconnect   trunk    full   unconf N/A                            
 Po120      POD20-LEAF1A                       notconnect   trunk    full   unconf N/A                            
 Po122      AP C-330 LAN1                      notconnect   trunk    full   unconf N/A

  2. Try some filtering of our output, there are some familiar filtering options like include, exclude, begin, etc, but as we go through this workshop we will explore further!

    Read Only Mode

    You have read only on the spines, which excludes access to EOS' underlying Linux subsystem. You will have full access to this in the workshop, where you can leverage tools like grep, awk, sed, etc to filter content further.

    show interfaces status | ?
show interfaces status | inc POD01
show interfaces | inc MTU|Eth
show interfaces | sec Ethernet(25|26)
    Example Output
    LINE      Filter command by common Linux tools such as grep/awk/sed/wc
append    Append redirected output to URL
begin     Start output at the first matching line
exclude   Do not print lines matching the given pattern
include   Print lines matching the given pattern
json      Produce JSON output for this command
no-more   Disable pagination for this command
nz        Include only non-zero counters
redirect  Redirect output to URL
section   Include sections that match
tee       Copy output to URL

  3. The spines in this workshop will act as our gateway for the various pods, let's validate our ip addressing and the virtual router addresses (gateways).

    show ip interface brief
show ip virtual-router
    Example Output
    Example Output: interface brief
                                                                                    Address
Interface         IP Address             Status       Protocol           MTU    Owner
----------------- ---------------------- ------------ -------------- ---------- -------
Ethernet49        192.168.254.1/31       up           up                9214
Management1       unassigned             down         down              1500
Vlan100           10.1.100.2/24          up           up                9214
Vlan101           10.1.1.2/24            up           up                9214
Vlan102           10.1.2.2/24            up           up                9214
Vlan103           10.1.3.2/24            up           up                9214
Vlan104           10.1.4.2/24            up           up                9214
Vlan105           10.1.5.2/24            up           up                9214
Vlan106           10.1.6.2/24            up           up                9214
Vlan107           10.1.7.2/24            up           up                9214
Vlan108           10.1.8.2/24            up           up                9214
Vlan109           10.1.9.2/24            up           up                9214
Vlan110           10.1.10.2/24           up           up                9214
Vlan111           10.1.11.2/24           up           up                9214
Vlan112           10.1.12.2/24           up           up                9214
Vlan113           10.1.13.2/24           up           up                9214
Vlan4094          192.168.255.1/30       up           up                9214
    Example Output: virtual-router
    IP virtual router is configured with MAC address: 00:1c:73:00:00:01
IP virtual router address subnet routes not enabled
IP router is not configured with Mlag peer MAC address
MAC address advertisement interval: 30 seconds

Protocol: U - Up, D - Down, T - Testing, UN - Unknown
        NP - Not Present, LLD - Lower Layer Down

Interface       Vrf           Virtual IP Address       Protocol       State
--------------- ------------- ------------------------ -------------- ------
Vl100           default       10.1.100.1               U              active
Vl101           default       10.1.1.1                 U              active
Vl102           default       10.1.2.1                 U              active
Vl103           default       10.1.3.1                 U              active
Vl104           default       10.1.4.1                 U              active
Vl105           default       10.1.5.1                 U              active
Vl106           default       10.1.6.1                 U              active
Vl107           default       10.1.7.1                 U              active
Vl108           default       10.1.8.1                 U              active
Vl109           default       10.1.9.1                 U              active
Vl110           default       10.1.10.1                U              active
Vl111           default       10.1.11.1                U              active
Vl112           default       10.1.12.1                U              active
Vl113           default       10.1.13.1                U              active

  4. Ok, let's look at all the LLDP information, note the models and EOS version details and interesting command atdpods. Explore the aliases configured on this device.

    show lldp neighbors detail
acwspods
show aliases
    Example Output
    Example Output: LLDP Detail
    Example Output: atdpods
    Interface Ethernet1 detected 1 LLDP neighbors:
   - System Description: "Arista Networks EOS version 4.31.6M running on an Arista Networks CCS-710P-12"
Interface Ethernet51 detected 1 LLDP neighbors:
   - System Description: "Arista Networks EOS version 4.31.6M running on an Arista Networks CCS-720XP-48ZC2"
Interface Ethernet52 detected 1 LLDP neighbors:
   - System Description: "Arista Networks EOS version 4.31.6M running on an Arista Networks CCS-720XP-48ZC2"
    Example Output: aliases
    acwspods        sh lldp neighbors detail | inc (detected 1|System Descr)
c               bash clear
sh-acg          trace monitor acg
sh-streaming    show agent TerminAttr logs | tail

  5. Let's look at traffic on our interfaces, let's also leverage the watch command with the nz (non-zero) command to monitor rates.

    show int counters rates
show int counters rates | nz
watch 1 diff show int counters rates | nz

  6. Sometimes it's the little things that make a big difference! This was a brief introduction into the CLI. All features start in EOS, with respective show and configuration commands. We'll further explore the symbiotic relationship between EOS and CloudVision!

    Wait! There's more!

    If you're interested in exploring more fun EOS commands, we published the Arista EOS Tips for Network Operators. If you would like access, ask your Arista team for more information!

    There are many more commands like:

    • Configuration sessions
    • CLI command finder
    • Event handlers
    • Event monitor
    • Packet captures
    • Scheduler
    • Tech Support Bundles/Checkpoints
    • So much more

MLAG & VARP

Arista's Multi-Chassis Link Aggregation (MLAG) is a technology that allows two physical switches to act as a single logical switch. By syncing the control plane without the need for proprietary cabling or protocols, it provides an active-active, non-blocking redundancy between multiple pairs of switches.

Let's explore the configuration and how to troubleshoot

  1. From the switch run the show mlag command to validate the high level state

    show mlag
    Example Output
    Example Output
    MLAG Configuration:
domain-id                          :                MLAG
local-interface                    :            Vlan4094
peer-address                       :       192.168.255.2
peer-link                          :      Port-Channel11
hb-peer-address                    :             0.0.0.0
peer-config                        :          consistent

MLAG Status:
state                              :              Active
negotiation status                 :           Connected
peer-link status                   :                  Up
local-int status                   :                  Up
system-id                          :   ae:3d:94:50:af:c6
dual-primary detection             :            Disabled
dual-primary interface errdisabled :               False

MLAG Ports:
Disabled                           :                   0
Configured                         :                   0
Inactive                           :                  13
Active-partial                     :                   0
Active-full                        :                   0

  2. You can also dive deeper in using the show mlag detail

    show mlag detail
    Example Output
    Example Output
    ...
MLAG Detailed Status:
State                           :              primary
Peer State                      :            secondary
State changes                   :                    2
Last state change time          :          4:56:38 ago
Hardware ready                  :                 True
Failover                        :                False
Failover Cause(s)               :              Unknown
Last failover change time       :                never
Secondary from failover         :                False
Peer MAC address                :    ac:3d:94:50:d2:aa
Peer MAC routing supported      :                 True
Reload delay                    :          300 seconds
Non-MLAG reload delay           :          300 seconds
Peer ports errdisabled          :                False
Lacp standby                    :                False
Configured heartbeat interval   :              4000 ms
Effective heartbeat interval    :              4000 ms
Heartbeat timeout               :             60000 ms
Last heartbeat timeout          :                never
Heartbeat timeouts since reboot :                    0
UDP heartbeat alive             :                 True
Heartbeats sent/received        :            4499/4450
Peer monotonic clock offset     :   -56.025806 seconds
Agent should be running         :                 True
P2p mount state changes         :                    1
Fast MAC redirection enabled    :                 True
Interface activation interlock  :         unconfigured

  3. Let's look at the configuration to enable MLAG, first run the command to show the block of mlag configuration

    show running-config section mlag configuration
    Example Output
    Example Output
    mlag configuration
    domain-id MLAG #(1)!
    local-interface Vlan4094 #(2)!
    peer-address 169.254.0.0 #(3)!
    peer-address heartbeat 10.1.1.4 #(4)!
    peer-link Port-Channel11 #(5)!
    dual-primary detection delay 5 action errdisable all-interfaces
    reload-delay mlag 300
    reload-delay non-mlag 330
    1. MLAG domain is locally significant to the MLAG pair of switches, this can be any descriptor. Whether it's simply MLAG like shown or the name of say a pod: POD01
    2. The local interface used to peer to the MLAG neighbor, this will always be an SVI
    3. The MLAG neighbors address that resides within the local-interface subnet
    4. This is an optional configuration called Dual Primary Detection, you can read more on this topic.
    5. The peer link is the layer 2 port-channel used to trunk our MLAG vlans, we'll explore below how that's configured.

  4. Let's take a closer look at the peer link itself

    run show run interface Eth25-26; show run int Port-Channel1000; show port-channel 1000 detailed
    Example Output
    Example Output
    !
interface Ethernet25
    description MLAG
    channel-group 25mode active
!
interface Ethernet26
    description MLAG
    channel-group 25 mode active
!
interface Port-Channel25
    description MLAG_spine2_Ethernet25
    switchport mode trunk
    switchport trunk group MLAG
!
Port Channel Port-Channel25 (Fallback State: Unconfigured):
Minimum links: unconfigured
Minimum speed: unconfigured
Current weight/Max weight: 2/8
Active Ports:
    Port             Time Became Active       Protocol       Mode         Weight    State
    ---------------- ------------------------ -------------- ------------ ------------ -----
    Ethernet25       11:51:27                 LACP           Active         1       Rx,Tx
    Ethernet26       9:24:02                  LACP           Active         1       Rx,Tx

  5. The port-channel is using a trunk group, lets look at that trunk group

    Linux Sub-system

    On top of the typical includes, section, begin, etc we commonly use to filter output. You also have access to many of the linux sub-system commands like grep, sed, awk, etc to filter and manipulate the output.

    show vlan trunk group | grep -E "MLAG|Groups|-"
    Example Output
    VLAN     Trunk Groups
----     ----------------------------------------------------------------------
4094     MLAG

  6. Note that vlan 4094 is a part of that trunk group, trunk groups are used to ensure those vlans assigned to trunk group MLAG are pruned from all interfaces except those explicitly configured. In this case Port-Channel11 is assigned the trunk group, therefore it's the only interface forwarding Vlan 4094.

  7. Let's look at the peering SVI Vlan4094

    show running-config interfaces vlan 4094
    Example Output: SPINE01
    interface Vlan4094
    description MLAG_PEER
    mtu 9200
    no autostate #(1)!
    ip address 169.254.0.0/31 #(2)!
    1. We disable autostate to force the VLAN to be active
    2. This peering address is only locally significant, it's common to use an APIPA IP address range (/31) that's repeated across all MLAG pairs. The neighbor address is used in the mlag configuration to peer over the trunk.

  8. In the previous show mlag section we got a brief overview of status. During troubleshooting steps, there is a built in command to ensure MLAG configuration parity between the two devices. Run the following command to validate configuration matches between the two devices

    show mlag config-sanity
    Example Output
    No global configuration inconsistencies found.

No per interface configuration inconsistencies found.

  9. Looking at the interfaces down to the POD, let's validate the interface configuration

    show run interface Ethernet 1-2
show run interface Port-Channel101
    Example Output
    Example Output
    !
interface Ethernet1
    description POD01
    switchport mode trunk
    channel-group 101 mode active
    lldp tlv transmit ztp vlan 101
!
interface Ethernet2
    description POD01
    switchport mode trunk
    channel-group 101 mode active
    lldp tlv transmit ztp vlan 101
!
interface Port-Channel101
    description POD01
    switchport trunk allowed vlan 101,201
    switchport mode trunk
    port-channel lacp fallback individual
    port-channel lacp fallback timeout 20
    mlag 101
!

  10. If we do detect issues or want to verify the MLAG interfaces upstream/downstream are up/up we can validate

    show mlag interfaces
    Example Output
    Example Output
    SPINE01#show mlag interfaces
                                                        local/remote
mlag       desc           state       local       remote          status
---------- ----------- -------------- ----------- ------------ ------------
101       POD01       inactive       Po101        Po101       down/down
102       POD02       inactive       Po102        Po102       down/down
103       POD03       inactive       Po103        Po103       down/down
104       POD04       inactive       Po104        Po104       down/down
105       POD05       inactive       Po105        Po105       down/down
106       POD06       inactive       Po106        Po106       down/down
107       POD07       inactive       Po107        Po107       down/down
108       POD08       inactive       Po108        Po108       down/down
109       POD09       inactive       Po109        Po109       down/down
110       POD10       inactive       Po110        Po110       down/down
111       POD11       inactive       Po111        Po111       down/down
112       POD12       inactive       Po112        Po112       down/down
113       POD13       inactive       Po113        Po113       down/down

  11. Lastly, how do we maintain active/active forwarding with MLAG, this where VARP comes in. A virtual router address and common MAC is all it takes.

    show run sec virtual-router
show ip virtual-router
    Example Output 
    !
interface Vlan101
    ip virtual-router address 10.1.1.1 #(1)!
interface Vlan102
    ip virtual-router address 10.1.2.1
interface Vlan103
    ip virtual-router address 10.1.3.1
...
!
ip virtual-router mac-address 00:1c:73:00:00:01 #(2)!
!

    IP virtual router is configured with MAC address: feed.dead.beef
IP virtual router address subnet routes not enabled
IP router is not configured with Mlag peer MAC address
MAC address advertisement interval: 30 seconds

Protocol: U - Up, D - Down, T - Testing, UN - Unknown
        NP - Not Present, LLD - Lower Layer Down

Interface       Vrf           Virtual IP Address       Protocol       State
--------------- ------------- ------------------------ -------------- ------
Vl1             default       192.168.3.1              U              active
Vl100           default       10.1.100.1               U              active
Vl101           default       10.1.1.1                 U              active
Vl102           default       10.1.2.1                 U              active
Vl103           default       10.1.3.1                 U              active
Vl104           default       10.1.4.1                 U              active
Vl105           default       10.1.5.1                 U              active
Vl106           default       10.1.6.1                 U              active
Vl107           default       10.1.7.1                 U              active
Vl108           default       10.1.8.1                 U              active
Vl109           default       10.1.9.1                 U              active
Vl110           default       10.1.10.1                U              active
Vl111           default       10.1.11.1                U              active
Vl112           default       10.1.12.1                U              active
Vl113           default       10.1.13.1                U              active
    1. This is the virtual IP address configured on both MLAG pairs.
    2. This vMAC will be used as the gateway vMAC associated with the Gateway VIP configured with either ip address virtual or ip virtual-router address (vARP). This vMAC will be consistent across all SVIs configured with a VIP.

  12. That's it for this lab, you should have a bit better understanding of how MLAG is configured

Closing Out

Streaming Telemetry

Let's take a look at the steaming telemetry agent that communicates back to CloudVision. You may not be able to do this on you switch (current in zero-touch). Feel free to come back to this section to explore, your instructor will showcase this.

  1. Let's view the telemetry agent daemon

    show running-config section TerminAttr
    Example Output 
    daemon TerminAttr
    exec /usr/bin/TerminAttr
        -disableaaa
        -cvaddr=apiserver.cv-prod-us-central1-b.arista.io:443
        -taillogs
        -cvproxy=
        -cvauth=certs,/persist/secure/ssl/terminattr/primary/certs/client.crt,/persist/secure/ssl/terminattr/primary/keys/client.key
        -smashexcludes=ale,flexCounter,hardware,kni,pulse,strata
    no shutdown

  2. Now let's see this in action, login to CloudVision and navigate to the Devices > Inventory

  3. Make a change to the hostname using a configuration session

    !
configure session namechange #(1)!
hostname SOMEONEWASHERE
!
show session-config diffs #(2)!
!
commit timer 00:05:00 #(3)!
    1. Create a configuration session, similar to branching in git, this will stage changes and wait for a commit to apply as a replace in configuration
    2. Show the differences of designed vs what's configured
    3. Commit the configuration to roll back in 5 minutes (hh:mm:ss), if you do not commit after the fact, this will roll back.
    Session Configuration Diff
    SPINE01[16:13:56](config-s-namechange)#show session-config diffs
--- system:/running-config
+++ session:/namechange-session-config
-hostname SPINE01
+hostname SOMEONEWASHERE

  4. You should see the hostname change immediately inside CloudVision! This is not a poll... this is a continuous stream of state from device to CloudVision.

Additional Fun Commands

There are few other commands you can explore in your lab after deployment. As we move away from the CLI, remember all interactions with Arista EOS both via terminal or automation are leveraging the same commands.

  • Bash

    Access to the underlying Linux system is available. Quick example is exploring the flash

    bash
cd /mnt/flash/
ls -latr

  • Packet Capture

    You have the ability to capture traffic, capturing control plane traffic or mirroring data plane to CPU.

    bash
tcpdump -vvvnei et1

  • AAA Logs

    Validate what commands have been run on the switch

    show aaa accounting logs | tail

  • Configuration Session

    Leverage a configuration session to stage config, commit as a full replace, and even configure a timed rollback.

    configure session ATD
!
hostname IWASHERE
!
show session-config diffs
!
commit timer 00:00:30
!
show conf sessions
!

🤖 AI Lab Assistant

Want to automate all the commands above? Use our embedded AI agent to execute the entire lab automatically!

🚀 A01 Lab Automation Agent

Let the AI handle the typing while you focus on learning the concepts!

Ready to start...
Command Output

🎉 CONGRATS! You have completed this lab! 🎉

LET'S GO TO THE NEXT LAB!