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I'm having a bit of trouble getting my routing right.

I have an HP v1910 switch with a a few VLAN interfaces. Let's take the first VLAN, VLAN10, which runs all my laptops etc... All VLANs connect via a trunk port to my router (Draytek Vigor 2920).

In my routing table I have a route that successfully sends data out to the internet. I know it works because I can access the internet. However, when trying to run a traceroute, I get the first IP (my VLAN interface) then *'s followed by my ISPs gateway IP address. I cannot work out why - I even SSH'd into the router and enabled ICMP echoing.

Surely the router should show up in my traceroute?

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  • Did any answer help you? If so, you should accept the answer so that the question doesn't keep popping up forever, looking for an answer. Alternatively, you could provide and accept your own answer.
    – Ron Maupin
    Aug 11, 2017 at 15:00

1 Answer 1

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traceroute (on *NIX systems) is using UDP to send out messages and the answers are icmp time exceeded. If your router dose not send these (or you block them on your side) you'll only see *. . tracert on Windows uses ICMP to send out packets. On *NIX you can switch to ICMP by using traceroute -I.

Another reason you may see * in a traceroute is that the router is just to busy sending out ICMP messages.

I already explained traceroute in more detail here

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  • The router used to show up. I've just checked all the syslogs and not seen any other problems. Apr 10, 2015 at 19:28
  • If you can capture network traffic on your router (e.g. by using tcpdump) see what happening..
    – user2084
    Apr 10, 2015 at 20:11

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