What does “TTL expired in transit” mean on a ping attempt

networkingpingtcpttl

We get the message “TTL expired in transit” when we try to ping to a server in a different network segment. When we run tracert, 4 ip addresses repeat themselves indefinitely:

14    60 ms    59 ms    60 ms  xxx.xxx.xxx.2
15    83 ms    81 ms    82 ms  xxx.xxx.xxx.128
16    75 ms    80 ms    81 ms  xxx.xxx.xxx.249
17    81 ms    78 ms    80 ms  xxx.xxx.xxx.250
18    82 ms    80 ms    77 ms  xxx.xxx.xxx.2
19   102 ms   101 ms   100 ms  xxx.xxx.xxx.128
20   101 ms   100 ms    98 ms  xxx.xxx.xxx.249
21    97 ms    98 ms    99 ms  xxx.xxx.xxx.250
...

What are the basic steps for troubleshooting this error?

Best Answer

As stated in all answers above there is loop in routing that is causing TTL to expire.

Check route on the devices whose IP addresses are repeating. On Linux you can use

route -n

as root user to see current routing table. On windows you can go to cmd and use command

route print

to see current routing table. On cisco manageable switches you can use command

show ip route

Using above commands on all the four IPs that are repeating you should see which routing table is wrong. One of the four devices / hosts involved should ideally route traffic to destination you are pinging using some other gateway.

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