[lug] Weird mail/firewall problem

[D. Stimits]

rm at fabula.de wrote:
...snip...
> > Just for kicks, maybe get your
> > failed email test on an interface, then use ifconfig to set to something
> > small on the interface itself, say 296 (power of 2 plus 40 assuming tcp
> > header), and see if it then gets through. Or maybe some other error
> > occurs.
> 
> That's a good diagnosis technique, indeed. Hmm, just to throw it in:
> you can also use 'tracepath':

Interesting tool, I like it. The man page didn't explain what asymm
means, hopefully someone here knows?

> 
> |  www:/home/ralf# tracepath www.zeit.de/80
> |  1?: [LOCALHOST]      pmtu 1500
> |  1?: 212.18.192.129
> |  2?: 212.18.192.22
> |  3?: 212.88.129.142
> |  4?: 213.248.68.101
> |  5?: 193.45.9.81
> |  6?: 213.248.68.90
> |  7?: 80.81.192.190    asymm  8
> |  8?: 212.38.193.205
> |  9?: 212.38.192.189   asymm  7
> | 10?: 212.38.221.33    asymm  6
> | 11?: 212.38.221.102   asymm  8
> | 12?: 194.64.3.101     asymm  9
> | 13?: 194.64.3.45      asymm  8
> | 14?: 194.163.251.75   asymm  9
> | 15:  194.163.254.175  asymm 10  23ms reached
> |      Resume: pmtu 1500 hops 15 back 10
> |
> 
> Same test from my firewall (attached to a DSL line):
> 
> | barrique:/home/moep# tracepath www.zeit.de/80
> |  1?: [LOCALHOST]      pmtu 1492
> |  1?: 217.5.98.41      asymm  5
> |  2?: 217.237.153.42
> |  3?: 62.154.18.46     asymm  8
> |  4?: 194.64.3.30      asymm  8
> |  5?: 195.180.3.209    asymm  8
> |  6?: 194.163.251.75   asymm  8
> |  7:  194.163.254.175  asymm  8 162ms reached
> |      Resume: pmtu 1492 hops 7 back 8
> |
> 
> another debuging tool would be 'hping'.

This one (hping) I don't have, I presume it gives ping information with
some extra data?

D. Stimits, stimits at idcomm.com

> 
>   Ralf
...snip...