tcpdump mailing list archives
Re: solaris loopback
From: Rick Jones <raj () tardy cup hp com>
Date: Wed, 12 Feb 2003 10:12:42 -0800 (PST)
Is it possible to do packet capture using the loopback device on solaris(dlpi)? I tried passing /dev/lo0 and got a pcap error: /dev/lo: No such file or directory. I see that the ethernet device /dev/hme0 is symbolically linked from /dev/hme -> /devices/pseudo/<some dev file> but this is not the case with the loopback lo0.
Given that lo0 is unlikely to be a DLPI device, it follows that it wold not work with tcpdump under Solaris (nor HP-UX for that matter - the two OSes TCP/IP stacks are distant "cousins"). Traffic sourced from and destined to a local IP may be similarly unavailable - on HP-UX at least the TCP/IP stack notices that the destination IP is local and the traffic won't even get to the NIC driver. On HP-UX there is an ndd tunable called ip_loopback_bypass that one can tweak to force the local IP traffic into the driver and thus past the tracing points. I'm not sure if that came into the stack after the Solaris stuff went its own way, but you might check that. However, that still won't do anything directly for loopback. You _might_ be able to manipulate the routes so that traffic for 127.0.0.1 is directed to one of your local IP's, and then set that flag and in that way be able to see 127.0.0.1 traffic. rick jones - This is the TCPDUMP workers list. It is archived at http://www.tcpdump.org/lists/workers/index.html To unsubscribe use mailto:tcpdump-workers-request () tcpdump org?body=unsubscribe
Current thread:
- solaris loopback Andrew Padilla (Feb 12)
- Re: solaris loopback Rick Jones (Feb 12)
- Re: solaris loopback Guy Harris (Feb 13)
- Re: solaris loopback Rick Jones (Feb 14)
- Re: solaris loopback Guy Harris (Feb 13)
- Re: solaris loopback Andrew Brown (Feb 12)
- Re: solaris loopback Guy Harris (Feb 13)
- Re: solaris loopback Andrew Brown (Feb 14)
- Re: solaris loopback Guy Harris (Feb 14)
- Re: solaris loopback Andrew Brown (Feb 14)
- Re: solaris loopback Guy Harris (Feb 13)
- Re: solaris loopback Rick Jones (Feb 12)