ASR9000/XR MC LAG with local xconnect

[dfranjoso]

Hello Guys,

Have anyone deployed a MC LAG with local xconnect.

For instance, having  POA A being the active node on the bundle-ether but the attachement circuit residing on the POA B. I don't think this is a supported topology, so i need your help guys.

Thanks!

David

[bhnegi]

I don't think LOCAL xconnect is supported over MC-LAG but it is for PW.

Supported MC-LAG topology

http://www.cisco.com/c/en/us/td/docs/routers/asr9000/software/asr9k_r5-2/interfaces/configuration/guide/hc52xasr9kbook/hc52lbun.html#pgfId-1221347

https://supportforums.cisco.com/document/9868751/asr9000xr-multichassis-lag-or-mc-lag-mclag-guide

P2P PW (coupled mode): bundle state determine the PW state. If bundle is in active state, then it advertise “active” PW status message.

Otherwise it will advertise “standby” PW status message to its peer Routers

The attachment circuit should be configured on both POA.

Best Regards,

Bheem

[dfranjoso]

Hello Bhnegi,

Can we use a VPLS with the following AC to overcome the issue:

• Bundle ether of the POA A (active)
• Bundle ether of the POA B (standby)
• Customer local AC on POA B

This way traffic will flow from POA A Bundle ether to the Customer AC on POA B via the VPLS and if for any reason POA B becames the active MC LAG node traffic will continue to flow to the Customer AC.

Am i seeing this correctly? Thanks!

PS: i am running 4.3.2

David

[bhnegi · Accepted solution]

I don't think configuring local connect on standby POA only  will have any effect as it would always be in standby. The downstream device will always have its link down towards standby POA in down state.

F340.03.13-ME-3600X-3#           sh etherchannel summary
Flags:  D - down        P - bundled in port-channel
        I - stand-alone s - suspended
        H - Hot-standby (LACP only)
        R - Layer3      S - Layer2
        U - in use      f - failed to allocate aggregator

        M - not in use, minimum links not met
        u - unsuitable for bundling
        w - waiting to be aggregated
        d - default port

Number of channel-groups in use: 1
Number of aggregators:           1

Group  Port-channel  Protocol    Ports
------+-------------+-----------+-----------------------------------------------
25     Po25(SU)        LACP      Te0/1(P)    Te0/2(w)    <<<<<<<<<<<<<<

F340.03.13-ME-3600X-3#sh int tenGigabitEthernet 0/2
TenGigabitEthernet0/2 is up, line protocol is down (notconnect)<<<<<<<<<<<<
  Hardware is Ten Gigabit Ethernet, address is 2c3f.3833.3a9a (bia 2c3f.3833.3a9a)

Best Regards,

Bheem