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Aniruddha Bohra
bohra at cs.rutgers.edu
Thu Jun 19 11:31:53 EDT 2003
Hi
I have attached the ifconfig and the route outputs for the two hosts.
And the behaviour is the same in both directions.
Ping works well and the TCP packet(SYN) does not.
And yes there is a telnet daemon running, but is it important
since I am not even seeing the SYN on tcpdump ?
Thanks for the reply
Aniruddha
Brecht Vermeulen wrote:
>Hello,
>
>I don't see directly the problem (because the ping works you say).
>If you configure the router as a simple linux router (echo 1 >
>/proc/sys/net/ip_forward I think), does it work then ?
>
>Does the ping work from host1 and from host 2 ?
>
>Does telnet the same thing (viewed with tcpdump on host 1 and 2) in the
>two directions ? If you use tcpdump -e you can also see the MAC adresses
>of the ethernet header. There is a telnet daemon running on host 2 ?
>
>Can you maybe post the routing tables on host 1 and host 2 (route -n)
>and the interface configurations (ifconfig) ?
>
>regards,
>Brecht
>
>Aniruddha Bohra wrote:
>
>
>>Hello
>> Using the same configuration as my previous message to the list
>>but adding several print statements, I have the following info :
>>Host 0 is on eth1 subnet - sends a SYN - which never reaches the Host1
>>on eth2
>>which however reaches at least the ARPQuerier (Out on eth2 printf).
>>
>>One thing to note is that the incoming packet is 60 bytes while the
>>outgoing packet is 58.
>>
>>/var/log/messages says
>>Jun 18 20:51:31 hora-7 kernel: chatter: eth1 IP: 60 | 000476df
>>ce580010 4200827c 08004510 002c0042 40004006
>>Jun 18 20:51:31 hora-7 kernel: chatter: Forward to eth2: 44 | 4510002c
>>00424000 400601b8 0a0a0a0e c0a86402 04140017
>>Jun 18 20:51:31 hora-7 kernel: chatter: Out on eth2: 58 | 00104200
>>827d0004 76dd2978 08004510 002c0042 40003f06
>>Jun 18 20:51:31 hora-7 kernel: chatter: Out on eth2: 42 | ffffffff
>>ffff0004 76dd2978 08060001 08000604 00010004
>>Jun 18 20:51:31 hora-7 kernel: chatter: Local delivery: 60 | 000476dd
>>29780010 4200827d 08060001 08000604 00020010
>>Jun 18 20:51:34 hora-7 kernel: chatter: eth1 IP: 60 | 000476df
>>ce580010 4200827c 08004510 002c0043 40004006
>>Jun 18 20:51:34 hora-7 kernel: chatter: Forward to eth2: 44 | 4510002c
>>00434000 400601b7 0a0a0a0e c0a86402 04140017
>>Jun 18 20:51:34 hora-7 kernel: chatter: Out on eth2: 58 | 00104200
>>827d0004 76dd2978 08004510 002c0043 40003f06
>>Jun 18 20:51:40 hora-7 kernel: chatter: eth1 IP: 60 | 000476df
>>ce580010 4200827c 08004510 002c0044 40004006
>>Jun 18 20:51:40 hora-7 kernel: chatter: Forward to eth2: 44 | 4510002c
>>00444000 400601b6 0a0a0a0e c0a86402 04140017
>>Jun 18 20:51:40 hora-7 kernel: chatter: Out on eth2: 58 | 00104200
>>827d0004 76dd2978 08004510 002c0044 40003f06
>>
>>tcpdump on host 0 says :
>>[root at ghoomar0 root]# tcpdump -i eth1
>>tcpdump: listening on eth1
>>19:52:16.467224 10.10.10.14.1044 > 192.168.100.2.telnet: S
>>3629135766:3629135766(0) win 5632 <mss 1460> (DF) [tos 0x10]
>>19:52:19.458799 10.10.10.14.1044 > 192.168.100.2.telnet: S
>>3629135766:3629135766(0) win 5632 <mss 1460> (DF) [tos 0x10]
>>19:52:25.458798 10.10.10.14.1044 > 192.168.100.2.telnet: S
>>3629135766:3629135766(0) win 5632 <mss 1460> (DF) [tos 0x10]
>>
>>tcpdump on host 1 says :
>>[root at ghoomar1 root]# tcpdump -i eth1
>>tcpdump: listening on eth1
>>20:55:32.978911 arp who-has 192.168.100.2 tell 192.168.100.1
>>20:55:32.978923 arp reply 192.168.100.2 is-at 0:10:42:0:82:7d
>>
>>Is there any more information I can provide to identify the problem ?
>>
>>Thanks
>>Aniruddha
>>
>>
-------------- next part --------------
eth0 Link encap:Ethernet HWaddr 00:06:5B:F3:A8:87
inet addr:128.6.171.252 Bcast:128.6.171.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:1381 errors:0 dropped:0 overruns:0 frame:0
TX packets:353 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:100
RX bytes:120308 (117.4 Kb) TX bytes:48447 (47.3 Kb)
Interrupt:28 Memory:fe3e0000-fe400000
eth1 Link encap:Ethernet HWaddr 00:10:42:00:82:7D
inet addr:192.168.100.2 Bcast:192.168.100.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:4 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:100
RX bytes:0 (0.0 b) TX bytes:168 (168.0 b)
Interrupt:100 Base address:0xb000
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:14 errors:0 dropped:0 overruns:0 frame:0
TX packets:14 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:1100 (1.0 Kb) TX bytes:1100 (1.0 Kb)
-------------- next part --------------
eth1 Link encap:Ethernet HWaddr 00:10:42:00:82:7C
inet addr:10.10.10.14 Bcast:10.10.10.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:4 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:100
RX bytes:0 (0.0 b) TX bytes:168 (168.0 b)
Interrupt:100 Base address:0xb000
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:10 errors:0 dropped:0 overruns:0 frame:0
TX packets:10 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:700 (700.0 b) TX bytes:700 (700.0 b)
-------------- next part --------------
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.100.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1
128.6.171.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
10.10.10.0 192.168.100.1 255.255.255.0 UG 0 0 0 eth1
127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo
0.0.0.0 128.6.171.129 0.0.0.0 UG 0 0 0 eth0
-------------- next part --------------
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.100.0 10.10.10.13 255.255.255.0 UG 0 0 0 eth1
128.6.171.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
10.10.10.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1
127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo
0.0.0.0 128.6.171.129 0.0.0.0 UG 0 0 0 eth0
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