I have got a RB 1000, if i trace route for the open DNS which is 208.67.222.222 using ICMP protocol it works out fine. But if i change the protocol to UDP it can not find the route to open DNS. Also when using ICMP i get a time out in between the route. Can anyone please help me. I am using VOIP phones which use UDP SIP connections and right now they can not make calls because they cant get to DNS.
Where is it being dropped?
Timeouts somewhere in an ICMP trace route are fairly normal. Some providers block ICMP on their equipment. It doesn’t necessarily indicate a problem.
please post exact results of both traceroutes
I have attached now both traceroute results. The time outs that i am getting are all at the ips that does not belong to my network. And you could see when doing a udp trace route it is showing me that the host is un reachable.
well, seems like it means that the host is not answering UDP packets =) and does not send ICMP rejects
If what you are telling is right , when i use icmp and ping 4.2.2.2 from rb1000 it reaches there but breaks multiple times in between the route. How could you define that?
You mean a traceroute to 4.2.2.2 times out on transient hops but reaches the target? The hops the traceroute traverses don’t respond to ICMP traceroutes.
When you traceroute to a target, the client first sends out an ICMP traceroute packet with a TTL of 1. The first router in the way receives it, decreases the TTL to 0 and reponds. The client then sends out another ICMP traceroute packet with a TTL of 2. The first router in the way receives it, decreases the TTL to 1 and forwards the packet to the next router. That next router decreases the TTL to 0 and responds. Your client does that until the target router responds, each time increasing the TTL by 1.
If a router in the way doesn’t respond to the traceroute packet, the traceroute on that hop will time out. Your client will still send another packet with a higher TTL to investigate the next hop.
But I’m not sure I understood the question right.
I have attached another traceroute. You could better understand my question now.
Then I did understand the question right, and my answer applies.