traceroute results in !A

[get_rthym]

Hello experts,

Hope everyone is well and doing good.

I came across a issue which i could not go further troubleshooting myself.

Issue Background:

CE site has 2 CE routers(CE1 and CE2), behind that has two l3 switches(L3SW1 and L3SW2). Each CE router has connection to both l3 switches and no connection exists between them. Actually CE1 has to links to L3SW1 via port fa0/1(10.1.3.1) and fa0/2 (10.1.4.1).

When i ping ip z.z.z.z/24 from CE1 works fine but from L3SW1 fails.

So, i did traceroute from L3SW1.

It goes like this.

10.1.3.1

10.1.4.1

10.1.3.1

10.1.4.1

!A!A

Both IP belongs to CE1 fa0/1 and fa0/2. But from router it's working fine.

I checked path from  CE1 it is direct and received via ebgp and its redistributed to lan via eigrp.

fa0/1 and fa0/2 is load sharing i guess.  I checked the access-list but could not get one which is blocking icmp.

Why it is looping and blocked via access-list when i cannot fine one that states blocking ?

What could be possibly happening?

Thank you very much in advance

[Zubair.Sayed_2]

Hi

Either there is no route somewhere or the ports between the switch and router are not configured as trunk links.

Are they in seperate vlans ?

[get_rthym]

Hello Sayed

Thank you for your time and reply.

Yes, ce1 ports fa0/1 and 0/2 are in diff vlan. From ce1 I receive z.z.z.z from ebgp and l3sw1 gets from ce1 via eigrp redistribution. I checked the routing table n found above.

What could b going wrong?

Sent from Cisco Technical Support iPhone App

[milan.kulik]

Hi,

check the routing for  the destination address z.z.z.z and aslo for the source IP address from the target device back to the

L3SW1.

Regarding the ACL: Don't forget Cisco is using UDP for traceroute packets, not ICMP.

HTH,

Milan