Routerboard not fragmenting packets... or so I think

RouterOS General
1

I have a location with a routerboard 230. Currently running 3.22 software. I’m having speed issues with it. I have other Mikrotik hardware in this town without issues, so it seems to be in this box. So far, I have figured out that maybe the traffic from access points behind it aren’t being fragmented. I tested this by doing pings to my main noc here with varying packet sizes. Anything over 1500 bytes ( the current MTU ) will just give an error ( packet too large and cannot be fragmented). Other devices just ping as usual and only quit if I check the don’t fragment checkbox.

Before I replace hardware on a perfectly working box other than this issue, I thought maybe someone can enlighten me. I have been working on this issue for a while and the ping issue is the only thing I have come up with.

Tom

2

Try using a Mangle rule on the forward chain to reset the don’t fragment flag for each packet and check if you are getting the same error from the client.

3

Thanks leonset for the response.

I do have the problem solved, I replaced the rb-230 with a rb-450 with version 5 software, problem solved. I don’t know if it was software or hardware, guess I’ll never know. I probably won’t upgrade that rb-230 past the version 3 that is on it.

Thanks.

Tom