Christopher Marshall wrote: > Joel: > > I am curious what would happen if you tried one of the simpler setups not > involving NAT. > > Say you have two physical hosts, A, and B, and one UML instance, C, running > on B. Let A and B be > connected to the same ethernet and let there be two /24 nets (10.0.1.0/24 and > 10.0.2.0/24) be > involved, something like this: > > A 10.0.1.1 eth0 > B 10.0.1.2 eth0 > B 10.0.2.1 tap0 > C 10.0.2.2 eth0 > > Let C's default GW be 10.0.2.1 and let A's GW to 10.0.2.0/24 be 10.0.1.2. > In other words, > on A: > route add -net 10.0.2.2 netmask 255.255.255.0 gw 10.0.1.2 > on C: > route add default gw 10.0.2.1 > > Enable packet forwarding on B: > echo "1" > /proc/sys/net/ipv4/ip_forward > > Then try pinging 10.0.1.1 from C and 10.0.2.2 from A. While you are doing > that, run > > tcpdump -i eth0 -n "icmp" > and > tcpdump -i tap0 -n "icmp" > > on B.
Pinging 192.168.0.1 from C produces tcpdump output from tap0, but none from eth0 on host B. I can't reverse the ping, as 192.168.0.1 is my dsl router. This does respond just fine to pings from my real host. I would just assume that, since no packets go out, none are likely to return. My own thought would be that the kernel on my host has no idea where or how to move them from tap0 to eth0, or else is dropping them. This is the output of route -n on B Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 10.0.0.0 0.0.0.0 255.255.255.0 U 0 0 0 tap0 192.168.0.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0 127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo 0.0.0.0 192.168.0.1 0.0.0.0 UG 0 0 0 eth0 I have been playing around with route, but so far haven't been able to figure out how to set a route from tap0 to eth0 or from 10.0.0.0 to 192.168.0.0. > > I would be suprised if that didn't work given that you have B<->C networking > working enough to ssh > from host to UML instance. > > Once you get this setup working, try adding NAT into the mix. Until you get > this simpler setup > working, trying to add NAT is just asking for trouble ;-) > > Chris Marshall > ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ User-mode-linux-user mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/user-mode-linux-user
