Re: mutilated IP over nullmodem

Rod Troch (troch@texas.com)
Wed, 22 May 1996 22:11:18 -0500 (CDT)


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Howdy,

Have you tried slowing down the link to something more reasonable (eg.
19200)? I am running SLIP over a 50' null modem cable @ 19.2Kb with no
broken packets. As a side, I just applied the 1.2.13 Masquerade patch to
my kernel source, rebuilt it, loaded it, installed the ipfw binary and
that too works like a champ over that null modem slip connection.

I am interested in hearing your results.

- -Rod

Rod Troch N2ZVV | Don't mess with TEXAS.
troch@texas.com | Lonestar - A Linux box
http://www.texas.com/ | FTP for Pgp key
"Don't ever ask anybody if they are from Texas; if they are, you'll
know it. If they aren't, you'll just make 'em feel bad." -Anonymous

On Sat, 11 May 1996, Herbert Rosmanith wrote:

>
> hello,
>
> on a 38kbit nullmodem line (both systems use a 16550a), i see truncated
> IP packets, regardless if using SLIP or CSLIP (havent tried PPP but I
> doubt it will make anydifference) ... I even saw an ICMP Source Quench :)
>
>
> any idea why this is happening ?
>
>
> herp@wildsau.idv.uni-linz.ac.at
>
> CSLIP
> 02:04:03.530204 truncated-ip - 1 bytes missing!192.168.1.250.1023 > 192.168.1.1.513: P 4175356476:4175356488(12) ack 761642696 win 13312 [tos 0x10]
> 02:04:11.590204 192.168.1.250.1041 > 192.168.1.1.23: S 213869027:213869027(0) win 512 <mss 256>
> 02:04:11.590204 192.168.1.1.23 > 192.168.1.250.1041: S 1095112669:1095112669(0) ack 213869028 win 13312 <mss 256>
> 02:04:11.630204 192.168.1.250.1041 > 192.168.1.1.23: . ack 1 win 13312
> 02:04:11.640204 192.168.1.250.1041 > 192.168.1.1.23: P 1:20(19) ack 1 win 13312
> 02:04:11.830204 truncated-ip - 7 bytes missing!192.168.1.250.1041 > 192.168.1.1.23: P 1:25(24) ack 1 win 13312
> 02:04:12.010204 192.168.1.1.23 > 192.168.1.250.1041: P 1:4(3) ack 1 win 13312
> 02:04:12.070204 192.168.1.250.1041 > 192.168.1.1.23: . ack 4 win 13312
> 02:04:12.460204 truncated-ip - 6 bytes missing!192.168.1.250.1041 > 192.168.1.1.23: P 1:25(24) ack 4 win 13312
> 02:04:13.260204 truncated-ip - 6 bytes missing!192.168.1.250.1041 > 192.168.1.1.23: P 1:25(24) ack 4 win 13312
> 02:04:14.860204 truncated-ip - 4 bytes missing!192.168.1.250.1041 > 192.168.1.1.23: P 1:25(24) ack 4 win 13312
> 02:04:18.060204 truncated-ip - 5 bytes missing!192.168.1.250.1041 > 192.168.1.1.23: P 1:25(24) ack 4 win 13312
> 02:04:23.630204 truncated-ip - 1 bytes missing!192.168.1.250.23 > 192.168.1.1.1149: P 3733217431:3733217434(3) ack 319492022 win 13312
> 02:04:24.460204 truncated-ip - 5 bytes missing!192.168.1.250.1041 > 192.168.1.1.23: P 1:25(24) ack 4 win 13312
>
> SLIP (no VJ)
> 02:05:12.410204 192.168.1.250.1042 > 192.168.1.1.23: S 274689560:274689560(0) win 512 <mss 256>
> 02:05:12.410204 192.168.1.1.23 > 192.168.1.250.1042: S 1155932659:1155932659(0) ack 274689561 win 13312 <mss 256>
> 02:05:12.450204 192.168.1.250 > 192.168.1.1: icmp: source quench
> 02:05:12.450204 truncated-ip - 39913 bytes missing!32.251.33.255 > 251.34.251.36: (frag 64771:39935@55488+) [tos 0xb4]
> 02:05:12.650204 truncated-ip - 6 bytes missing!192.168.1.250 > 192.168.1.1: icmp: source quench
> 02:05:13.050204 truncated-ip - 5 bytes missing!192.168.1.250 > 192.168.1.1: icmp: source quench
> 02:05:15.400204 192.168.1.1.23 > 192.168.1.250.1042: S 1155932659:1155932659(0) ack 274689561 win 13312 <mss 256>
> 02:05:18.200204 truncated-ip - 5 bytes missing!192.168.1.250 > 192.168.1.1: icmp: source quench
> 02:05:18.210204 truncated-ip 4
> 02:05:18.210204 truncated-ip 3
> 02:05:18.650204 truncated-ip - 7 bytes missing!192.168.1.250 > 192.168.1.1: icmp: source quench
> 02:05:21.400204 192.168.1.1.23 > 192.168.1.250.1042: S 1155932659:1155932659(0) ack 274689561 win 13312 <mss 256>
>
>

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