Subject: Nasty net problem.. Jay, I was having a what appeared to be a hardware problem on glint2 today (link light flashing on/off on external tranceiver and a zillion framing errors.) To try to isolate the problem I swapped tranceivers with jmw3 and swapped cables with glint3. That seemed to solve the glint2 problem, but now I am having a problem similar to one Wayne said you had. Namely glint3 can apparently access all systems EXCEPT glint and glint2. If I try to ping glint from glint3 here is what happens: Running tcpdump on glint I see the normal arp request and arp response: 15:47:28.438147 arp who-has glint.cs.clemson.edu tell glint3.cs.clemson.edu 15:47:28.438194 arp reply glint.cs.clemson.edu is-at 0:60:97:1a:6d:39 15:47:29.438091 arp who-has glint.cs.clemson.edu tell glint3.cs.clemson.edu 15:47:29.438134 arp reply glint.cs.clemson.edu is-at 0:60:97:1a:6d:39 15:47:30.438073 arp who-has glint.cs.clemson.edu tell glint3.cs.clemson.edu 15:47:30.438109 arp reply glint.cs.clemson.edu is-at 0:60:97:1a:6d:39 Running tcpdump on glint3 I see only the arp request and not the arp response: 13:29:51.327375 arp who-has glint.cs.clemson.edu tell glint3.cs.clemson.edu 13:29:52.327417 arp who-has glint.cs.clemson.edu tell glint3.cs.clemson.edu 13:29:53.327373 arp who-has glint.cs.clemson.edu tell glint3.cs.clemson.edu 13:29:54.327375 arp who-has glint.cs.clemson.edu tell glint3.cs.clemson.edu All of my firewalling is OFF, and perversely I can ping any other system from glint3 and glint3 from any other systems. Here is from jmw2 /home/westall ==> ping glint3 PING glint3.cs.clemson.edu (130.127.48.243): 56 data bytes 64 bytes from 130.127.48.243: icmp_seq=0 ttl=255 time=0.6 ms 64 bytes from 130.127.48.243: icmp_seq=1 ttl=255 time=0.5 ms 64 bytes from 130.127.48.243: icmp_seq=2 ttl=255 time=0.5 ms 64 bytes from 130.127.48.243: icmp_seq=3 ttl=255 time=0.5 ms 64 bytes from 130.127.48.243: icmp_seq=4 ttl=255 time=0.5 ms Here is from jmw3 PING glint3.cs.clemson.edu (130.127.48.243): 56 data bytes 64 bytes from 130.127.48.243: icmp_seq=0 ttl=255 time=1.3 ms 64 bytes from 130.127.48.243: icmp_seq=1 ttl=255 time=0.8 ms 64 bytes from 130.127.48.243: icmp_seq=2 ttl=255 time=0.7 ms 64 bytes from 130.127.48.243: icmp_seq=3 ttl=255 time=0.7 ms Here is from glint3 to glint and then to atm2 /home/westall ==> ping glint PING glint.cs.clemson.edu (130.127.48.143): 56 data bytes --- glint.cs.clemson.edu ping statistics --- 518 packets transmitted, 0 packets received, 100% packet loss /home/westall ==> ping atm2 PING atm2.cs.clemson.edu (130.127.56.30): 56 data bytes 64 bytes from 130.127.56.30: icmp_seq=0 ttl=254 time=3.0 ms 64 bytes from 130.127.56.30: icmp_seq=1 ttl=254 time=0.7 ms 64 bytes from 130.127.56.30: icmp_seq=2 ttl=254 time=0.7 ms 64 bytes from 130.127.56.30: icmp_seq=3 ttl=254 time=0.7 ms 64 bytes from 130.127.56.30: icmp_seq=4 ttl=254 time=0.7 ms --- atm2.cs.clemson.edu ping statistics --- 5 packets transmitted, 5 packets received, 0% packet loss round-trip min/avg/max = 0.7/1.1/3.0 ms /home/westall ==> Here are all routing tables: /home/westall ==> /sbin/route Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 130.127.48.243 * 255.255.255.255 UH 0 0 0 eth0 130.127.48.0 * 255.255.255.0 U 0 0 0 eth0 127.0.0.0 * 255.0.0.0 U 0 0 0 lo default 130.127.48.1 0.0.0.0 UG 0 0 0 eth0 /home/westall ==> ==> /sbin/route Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 130.127.48.190 * 255.255.255.255 UH 0 0 0 eth0 130.127.48.0 * 255.255.255.0 U 0 0 0 eth0 127.0.0.0 * 255.0.0.0 U 0 0 0 lo default 130.127.48.1 0.0.0.0 UG 0 0 0 eth0 ==> [root@glint westall]# /sbin/route Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 130.127.48.143 * 255.255.255.255 UH 0 0 0 eth0 130.127.48.0 * 255.255.255.0 U 0 0 0 eth0 127.0.0.0 * 255.0.0.0 U 0 0 0 lo default 130.127.48.1 0.0.0.0 UG 0 0 0 eth0 [root@glint westall]# Finally here is ifconfig on glint3 indicating that there aren't a gezillion errors going on: /home/westall ==> /sbin/ifconfig eth0 Link encap:Ethernet HWaddr 00:B0:D0:11:91:C4 inet addr:130.127.48.243 Bcast:130.127.48.255 Mask:255.255.255.0 UP BROADCAST RUNNING PROMISC MULTICAST MTU:1500 Metric:1 RX packets:28911 errors:0 dropped:0 overruns:0 frame:0 TX packets:4067 errors:0 dropped:0 overruns:0 carrier:2 collisions:7 txqueuelen:100 Interrupt:19 Base address:0xdc00 As a final test I have now swapped the cables to glint2 and glint3 back to their original configuration. The "ping" problem followed the cable. Now glint and glint3 can ping each other fine but neither can ping glint2. Meanwhile glint2 can't ping glint or glint3 but it CAN reach the rest of the world. This is beginning to look to me that the resolution resides in the wiring closet. So maybe you should just pass this on to CCR and crew. Mike