HSRP

[tuelo0001]

Am running HSRP in all the sites

Both branches are connecting to the head office as per the scenario

I have configured ip sla on the active routers to track reachability of the links. If the link goes down, they will decrement priority by 50 to allow standby routers to take over.

My challenge is, when the active link from branch 2 to head office goes down, the standby router at branch 2 takes over and tries to route traffic to head office via branch 1.  This does not work because the router that is connected to at branch 1 is not the active router. (it’s on standby because the primary link is still UP)

It only works if the primary link from branch 1 to head office also goes down.

How can I overcome this??

[Jon Marshall]

It should make no difference whether the router is active or standby as long as it has routes to the destination subnets.

HSRP active/standby does not determine whether the router will forward or not.

Jon

[Joseph W. Doherty]

As Jon has already noted, HSRP, alone, shouldn't be causing the issue you've described.  I would suspect you have some routing configuration issue.  How is your routing configured?  What are your WAN links?

[tuelo0001]

thank you,

am just using static routes at the moment and will re-visit my configuration to check

[tuelo0001]

[tuelo0001]

i can only get to (Branch 1) 192.168.2.0/24 network from (Branch 2) only if i make the current standby router Active

[Jon Marshall]

Please post from both routers in Branch 1 -

"sh ip route 192.168.3.0 255.255.255.0"

Jon

[Joseph W. Doherty]

Also from branch 1's standby

"sh ip route 192.168.1.0 255.255.255.0"

BTW, you didn't answer my question about the nature of your WAN links.  What's reason you don't want to use the standby links other then when there's a failure?

Also have you consider using a dynamic routing protocol?

[tuelo0001]

Branch1-Secondary#sh ip route 192.168.1.0 255.255.255.0
Routing entry for 192.168.1.0/24
  Known via "static", distance 1, metric 0
  Routing Descriptor Blocks:
  * 2.2.2.2
      Route metric is 0, traffic share count is 1

The standby links were put in place for backup in case the primary links are down.

i am not an expect on the field, so if there is any better way of doing it, please kindly advise

[Joseph W. Doherty]

Is the secondary link up?  For example, from branch 1 standby, can you ping the other side of the secondary link, 2.2.2.2?

As to if there's a better way, it depends on the nature of your WAN links.  For example, between the HO and branch 1 you might want to use both links concurrently.  Or, even if primary links active, for any traffic between branches, you might want to use the inter branch link rather than bouncing off HO.

[tuelo0001]

The secondary links are UP

From branch 1 secondary, i can ping 2.2.2.2 (HO secondary) and 2.2.2.6 (Branch 2 secondary)

But still on the secondary routers, i cannot ping LAN devices unless i turn off my active routers and the standby/secondary routers become active.

[Joseph W. Doherty]

Still sounds like a routing configuration issue, but we would need to check all your routers' static route assignment.  So easy to muck things up with static routing once you get beyond a few devices.

Again, you might want to consider using dynamic routing (assuming your devices support it).

In the meantime, what do you see with a traceroute from branch 2's standby to a host on HO LAN, when branch 2 <> HO primary is down?

[tuelo0001]

Branch1-primary#ping 192.168.3.1

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.3.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/4 ms
Branch1-primary#sh ip route 192.168.3.0 255.255.255.0
% Network not in table
=====================================================================

Branch1-Secondary#ping 192.168.3.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.3.1, timeout is 2 seconds:
.....
Success rate is 0 percent (0/5)
Branch1-Secondary#sh ip route 192.168.3.0 255.255.255.0
Routing entry for 192.168.3.0/24
  Known via "static", distance 1, metric 0
  Routing Descriptor Blocks:
  * 2.2.2.6
      Route metric is 0, traffic share count is 1

[Jon Marshall]

On the active router in Branch 1 you do not have a route for 192.168.3.0/24 so I suspect you have a default route pointing to HO.

Which means that return traffic to 192.168.3.0/24 from Branch 1 always goes via HO even if the link is down from HO to Branch 2.

The simple solution is to add a route to the active router in Branch 1 for the 192.168.3.0/24 subnet pointing to the standby router in Branch 1 but that would only fix this specific issue and there may be others because of the way the WAN is connected.

It really would make sense to let a dynamic routing protocol handle this as it would be automatic but it may not meet your requirements.

Jon