Add more interfaces on 6880X L3 port-channel

[Bel Marsad]

Hello,

We have already a L3 port channel configured and running between two pair VSS of 6880X and 6500 with two interfaces and would like to add two more interfaces, I plan to do it like below:

Configure both new interfaces as the interfaces already configured on the existing L3 Po on both 6880X and 6500 let them shutdwon and once both interfaces configuration are done I do a no shut to join them to the bundle, but  my question is, I have to do no shut four time (twice on the 6880X side and two time on the 6500 side) as I cannot do it at same time I would like to know if there will be an impact/outage on the exsiting Port-channel? or I can do it without any risk?

If you have better idea also to config/join those two new interfaces please advise.

Thanks

Belmar

[Mark Malone]

You can narrow it down  with the range command as example below , but either way you should be fine should be no risk as PO is already formed they will only join when both sides are matched and up

(config)#int range g3/10, g3/44
(config-if-range)#no shut

[Bel Marsad]

Thanks for your quick answer

my new interfaces are configured as below:

interface TenGigabitEthernet1/2/25

description --- NewL3

shutdown

no switchport

no ip address

logging event link-status

At this stage the interfaces is down, my question is once I pass the command below to the switch as the Po11 is already up

doesn’t bring up automatically the interface? or I have to do no shut manually and if the Po bring up the interface what happen as I didn’t yet configured other end ?

channel-group 11 mode active

Could you please let me know the exact sequence on both side ?

Many Thanks for your help

[Mark Malone · Accepted solution]

add the channel-group command in , it wont do anything until both sides are up and yes it needs to be manually no shut it wont auto come up , its LACP so it needs to negotiate with both sides first , you can have links up and down in a PO it makes no difference to the PO itself

as you can see from some of my VSS pos there already like that as I'm always moving stuff about

7 Po7(SU) LACP Gi1/4/40(P) Gi1/4/41(D) Gi2/4/40(P)
Gi2/4/41(D)

Just out of interest is there no access vlan or trunk settings to go in it ?

[Bel Marsad]

Thanks got it.

about your last question I didnt understand ? the Po its L3 so no trunk or access vlan...

How about impair number of interfaces ? can I have only three interfaces on a Po or its mandatory to have four ?

[Mark Malone]

sorry my bad if its L3 :)

You can have 3 but remember the load balancing options

For me on our VSS setup this works well for us below and when we check we can see its utilizing all our members , you can have 8 members but the traffic may only be using 2 so its just as important to get the load balancing right so as many as possible are used to distribute the traffic

port-channel load-balance src-dst-port

some switches have a lot of options

(config)#port-channel load-balance ?
  dst-ip                      Dst IP Addr
  dst-mac                     Dst Mac Addr
  dst-mixed-ip-port           Dst IP Addr and TCP/UDP Port
  dst-port                    Dst TCP/UDP Port
  mpls                        Load Balancing for MPLS packets
  src-dst-ip                  Src XOR Dst IP Addr
  src-dst-mac                 Src XOR Dst Mac Addr
  src-dst-mixed-ip-port       Src XOR Dst IP Addr and TCP/UDP Port
  src-dst-port                Src XOR Dst TCP/UDP Port
  src-ip                      Src IP Addr
  src-mac                     Src Mac Addr
  src-mixed-ip-port           Src IP Addr and TCP/UDP Port
  src-port                    Src TCP/UDP Port
  vlan-dst-ip                 Vlan, Dst IP Addr
  vlan-dst-mixed-ip-port      Vlan, Dst IP Addr and TCP/UDP Port
  vlan-src-dst-ip             Vlan, Src XOR Dst IP Addr
  vlan-src-dst-mixed-ip-port  Vlan, Src XOR Dst IP Addr and TCP/UDP Port
  vlan-src-ip                 Vlan, Src IP Addr
  vlan-src-mixed-ip-port      Vlan, Src IP Addr and TCP/UDP Port