cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
1189
Views
0
Helpful
10
Replies

Catalyst 6504-E with SUP-720-10G WAN interfaces confusion

remi-reszka
Level 1
Level 1

Hi,

I have a one chassis Catalyst 6504-E with 2 x SUP-720-10G working in SSO mode. My understanding was that the supervisor WAN interfaces are only configurable on the active supervisor and they are replicated to the standby supervisor. It looks like I can configure all the WAN interfaces on both supervisors independently. Can it be done that WAN interfaces are configured only on the active supervisor and their configuration is a mirror to the WAN interfaces on the standby supervisor?

The requirement here is that I have 2 carriers (running BGP with same ASN to both of them) and one carrier is active and the second carrier is my backup. So only one WAN interface should be active at a time (the one on the active sup). So to speak the active carrier would be connected to the active supervisor and the backup carrier should be connected to the standby supervisor.

Can it be achieved this way?

Thanks for any clues and suggestions.

Remy

10 Replies 10

Mark Malone
VIP Alumni
VIP Alumni
Hi
Yes thats correct
In chassis configurations where there are redundant supervisor engines installed, the uplink ports on the supervisor engine that is in standby mode are fully functional.

Are they routed layer 3 or layer 2 links ?
if its BGP links you could use the metrics to make one favorable , doc below specific section shows how to
If there layer 2 just use STP set the cost so high that it becomes a redundant backup link , spanning-tree cost 100000

https://www.cisco.com/c/en/us/support/docs/ip/border-gateway-protocol-bgp/13762-40.html#anc9
Load Sharing When Dual-Homed to One Internet Service Provider (ISP) Through a Single Local Router

Thanks Mark for your comments. Yes, the uplinks are configured as routed L3 ports. So there is no way to configure the 2 supervisors in a way that the standby supervisor would be the mirror of the active one? Say in a similar way like ASA Active-Standby?

Regards,

Hi
unfortunately what im reading is no unless someone else has seen something different , there active for the customer so they can use them and not be left in a redundant state

off my head if this has to be that way , you could use an EEM script
base it off a syslog event that appears in logs when the new sup changes over , have the interfaces in shut down state but when it sees the syslog messages EEM kicks in and brings up the links , might be a bit messy but would work

Thank you Mark. Yes I had the same thought to go with EEM and already did some test. Here I would need to have one EEM script for when the primary carrier goes down to switch over to the secondary carrier and another EEM script for when an active supervisor goes down. It's the question of catching the right syslog messages. I wonder when the secondary supervisor takes over the active role will it be able to still execute EEM scritp once it became active? Once I think I ran some EEM script with the time delay and based on a syslog message that should help.

 

Best regards,

Remy

Good point i was thinking off my head but i knew it may be 50/50, time delay is a good option but i wonder when it switches over would the script be still running as the stream would be broke and it may not continue over from the same point time delay or not as its now being driven by a different sup , if you put a switch in front of the 65 may solve the issue as you could use a port channel then between the 65 and the switch ,then you could make the carrier circuits load balance or be active standby whatever you need without the worry of the sups interfaces being active

True and it would be interesting to verify that in the lab. The carriers will connect directly to the supervisors so no other switch option in front of the chassis. I will test that and let you know. Although running BGP with the carriers and prioritize them also would be an option. Once tested in the lab I will let you know, I bed you are curious if the EEM would work in this scenario.

Regards,

Remy

Reza Sharifi
Hall of Fame
Hall of Fame

Hi,

The requirement here is that I have 2 carriers (running BGP with same ASN to both of them) and one carrier is active and the second carrier is my backup. So only one WAN interface should be active at a time (the one on the active sup). So to speak the active carrier would be connected to the active supervisor and the backup carrier should be connected to the standby supervisor.

Can it be achieved this way?

The only way that this might work is by using a layer-3 Portchannle where you have one link from the primary sup and one from the standby sup in the same channel group but for this, to work you have to talk to your provider to do the same on their side. So, it would be one layer-3 Portchannel with one /30 IP.  Note that layer-3 Portchannel is supported on the 6500 but not sure about the ports on the sups. This is something you would have to test.  A better solution would be to have each circuit going to a different router with one /30 for each connection, EBGP with the service provider and IBGP between the 2 chassis.

HTH

 

 

Thank you for your suggestions, I will test that.

 

BTW, these are not necessarily "WAN" interfaces, there are simply 10Gig  Ethernet ports that can be used for anything. (WAN, LAN, layer-2, layer-3, connecting to servers, etc..).

HTH

Correct. I simply used here term WAN interfaces as for they purpose in this configuration and as they connect directly with the carrier. Thanks.

Getting Started

Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community: