I have an weird intermittent network problem and I am running out of ideas!
Last week I upgraded my sever to OpenSuSE 12.3 and right from the install it was having difficulty verifying internet connectivity.
Server 192.168.2.1, SuSE 12.3
Gateway 192.168.2.138, IPCop 2.0.6
Gigabit switch, no wireless.
The configuration seems fine.
eth0 Link encap:Ethernet HWaddr 00:24:8C:06:61:7D
inet addr:192.168.2.1 Bcast:192.168.2.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:306484 errors:24 dropped:2094 overruns:23 frame:1
TX packets:151440 errors:0 dropped:0 overruns:0 carrier:0
RX bytes:319127546 (304.3 Mb) TX bytes:14483317 (13.8 Mb)
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:3573 errors:0 dropped:0 overruns:0 frame:0
TX packets:3573 errors:0 dropped:0 overruns:0 carrier:0
RX bytes:259788 (253.6 Kb) TX bytes:259788 (253.6 Kb)
Routing also seems OK.
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
0.0.0.0 192.168.2.138 0.0.0.0 UG 0 0 0 eth0
127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo
169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth0
192.168.2.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
And ARP is also OK
Address HWtype HWaddress Flags Mask Iface
192.168.2.25 ether bc:ae:c5:6f:c6:f1 C eth0
192.168.2.138 ether 00:19:66:8a:62:8f C eth0
The weird thing is I can connect to the server with SSH with no problem (that’s from 192.168.2.25). The gateway router can ping the server all the time. But the server occasionally just stops being able to send packets to the router. At the same time, the server can ping the printer for instance, just not the router.
No error messages, nothing in log/messages, it just fails. Nothing in the logs on the router. The server firewall is off BTW.
Tcpdump on the server claims to be sending, tcpdump on the router claims nothing arrives from the server, but can see packets from other sources.
Then some time later it works again.
I tried SMEserver on the same hardware last week. It worked fine with the network but I found it a bit to restrictive so went back to Suse.
BTW in case anyone is wondering why the gateway is at 192.168.1.138, it used to be on a 10mbit segment at 192.168.1.1 and 192.168.2.1 was the gateway to that segment. I got rid of the 10mbit segment and put the router on the high speed net but never got around to giving it a more conventional address.