Is it possible another router somewhere is announcing x.x.x.208/28 (or /29 or /30)? You mentioned there is no x.x.x.208/32 router in the route table, but what about other prefix lengths?

Are you summarizing your PPPoE prefixes into OSPF by putting them into another area and using area-ranges or do all the /32s just end up in all your routers' tables as PPPoE sessions come up?

Did you look at the route tables at Braggcity and Ross to ensure they show the correct outgoing iface for that /32 to reach the Hayti router?

Are you using MPLS at all?

If you add a static route for x.x.x.208/32 to Bernie, Braggcity and Ross, does that make any difference?

Jesse DuPont

Network Architect
email: jesse.dup...@celeritycorp.net
Celerity Networks LLC

Celerity Broadband LLC
Like us! facebook.com/celeritynetworksllc

Like us! facebook.com/celeritybroadband

On 8/25/16 11:22 AM, Robert Haas wrote:

Alright, this problem has raised it head again on my network since I started to renumber some PPPoE pools.

Customer gets a new IP address via PPPoE x.x.x.208/32 (from x.x.x.192/27 pool). Customer can’t surf and I can’t ping them from my office:

 

[office] – [Bernie Router] – [Braggcity Router] – [Ross Router] – [Hayti Router] – [customer]

 

A traceroute from my office dies @ the Bernie router but I am not getting any type of ICMP response from the Bernie router ie no ICMP Host Unreachable/Dest unreachable etc – just blackholes after my office router.

A traceroute from the Customer to the office again dies at the Bernie router with no type of response.

 

Checking the routing table on the Bernie router shows a valid route pointing to the Braggcity router. It is also in the OSPF LSA’s.

--

Another customer gets x.x.x.207/32 and has no issue at all.

 

--

Force the original customer to a new ip address of x.x.x.205/32 and the service starts working again.

 

--

 

Now – even though there is no valid route to x.x.x.208/32 in the routing table – traffic destined to the x.x.x.208/32 IP is still getting blackholed.. I should be getting a Destination host unreachable from the Bernie router.

 

This is correct the correct response .206 is not being used and there is no route to it:

C:\Users\netadmin>ping x.x.x.206

 

Pinging x.x.x.206 with 32 bytes of data:

Reply from y.y.y.1: Destination host unreachable.

Reply from y.y.y.1: Destination host unreachable.

 

Ping statistics for x.x.x.206:

    Packets: Sent = 2, Received = 2, Lost = 0 (0% loss),

 

C:\Users\netadmin>tracert 74.91.65.206

 

Tracing route to host-x.x.x.206.bpsnetworks.com [x.x.x.206]

over a maximum of 30 hops:

 

  1     6 ms     6 ms     7 ms  z.z.z.z

  2     6 ms     6 ms     6 ms  y.bpsnetworks.com [y.y.y.1]

  3  y.bpsnetworks.com [y.y.y.1]  reports: Destination host unreachable.

 

Trace complete.

 

This is what I see to x.x.x.208 even though it is not being used and there is no route to it.

C:\Users\netadmin>ping x.x.x.208

 

Pinging x.x.x.208 with 32 bytes of data:

Request timed out.

Request timed out.

 

Ping statistics for x.x.x.208:

    Packets: Sent = 2, Received = 0, Lost = 2 (100% loss),

 

C:\Users\netadmin>tracert x.x.x.208

 

Tracing route to host-x.x.x.208.bpsnetworks.com [x.x.x.208]

over a maximum of 30 hops:

 

  1     6 ms     6 ms     6 ms  z.z.z.z

  2     *        *        *     Request timed out.

  3     *        *     ^C

 

--

 

I’ve verified there is no firewall that would affect the traffic – I even put an accept rule in the forward chain for both the source and destination of x.x.x.208 and neither increment at all. So the traffic is not even making out of the routing flow and into the firewall..

 

Any pointers are where to start troubleshooting next?


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