Nathan Neulinger wrote:
>
> I'd like to suggest that a useful feature would be a menu item that did
> "resolve addresses", and perhaps one on the per-packet right-click menu
> as well to do it just for that packet.
>
> I don't know how much trouble this would be to implement, but it seems
> like it shouldn't be too difficult to go back and resolve addresses for
> previous frames at a later time.
>
It should be quite simple. Note that you can achieve a similar result by
capturing or loading a file with name resolution disabled (e.g. -n option)
and then re-enable it thanks to the option window. Then, each time, you
select a packet, the IP addresses will be resolved in the detailed tree.
This works even in a live capture mode (it is better to let the option
window opens and click on apply instead of OK to switch off/on easily :-).
> -- Nathan
>
> Guy Harris wrote:
> >
> > > > (Oh, and, if you do this, make sure you'd run Ethereal with name
> > > > resolution turned off; I'm not sure which particular call the DNS or NIS
> > > > name-lookup code uses to read replies, but I'd rather not have to worry
> > > > about whether the "recvfrom()" is receiving a packet from the socket
> > > > it's using for snooping or from a socket it's using for making requests
> > > > over the network.)
> > >
> > > That's it! When I turn off name resolution, everything is fine.
> >
> > DNS lookups often take a really long time to time out if the DNS server
> > isn't responding. When Ethereal is reading in a capture - or when it's
> > doing an "update the screen as packets come in" capture - it will, by
> > default, try to translate IP addresses to host names, which can cause it
> > to hang for a while until the OS's DNS resolver finally times out and
> > gives up.
> >
The resolv.c code is protected against long DNS timeout (there is a longjmp
after, currently, 2 seconds).
Laurent.
--
Laurent DENIEL | E-mail: deniel@xxxxxxxxxxx
Paris, FRANCE | laurent.deniel@xxxxxxxxxxxxxxxxxxxxxxxxxxxx
| WWW : http://www.worldnet.fr/~deniel
All above opinions are personal, unless stated otherwise.