Routing

Hi, can anyone tell me what the difference is between ping and ping with the record route option? Looking int o a problem at work whereby a user cannot conenct to a website. When I do a traceroute, it stops at our MX series router.

If I jump onto the router and do a show route x.x.x.x there is a route vin the routing table (in fact there are several). The one with the highest local pref is via a peering partner.

Now the strange bit, if I do ping or traceroute x.x.x.x it does not get there, but it I do a ping record-route x.x.x.x it can ping and trace the path. So I think somehow the record route option is selecting a different route, can anyone explain why this would occur with the record-route option. 

No firewall filters or anything liek like blocking it, I'm guessing it must be a duff route coming from the peer. Thanks in advance for any light shed on this.

You have the answer in your question.

ping will test network connectivity to a host (not always correct because some admins disable the ping response or a firewall may prevent a response) and simply give a reply from the host

ping record route - test connectivity to the host and also shows the path the packet takes back to the source of the ping.

Do you have unicast RPF enabled?

You may also want to look and routing polices which can make one path suboptimal for return traffic.

Ping- normally used to check connectivity

ping record route- checks the path in both direction ( forward and reverse), quite useful to check asymmetric routing. You can say, It is an advance form of traceroute.

Hope it help!

Thanks

MYN