On Sat, Feb 23, 2002 at 02:45:35PM +0200, Ruslan Ermilov wrote:
[snip]

> Router B: if0 (192.168.1.1/24) and if1 (192.168.4.1/24)
> Router A: if0 (192.168.1.2/24)
> 
> On router A: route add -net 192.168.4 192.168.1.1, telnet 192.168.4.255.
> 
> Or even simpler:
> 
> Router: if0 (192.168.1.1/24 and 192.168.100.1/24)
> Host: if0 (192.168.1.2, default gateway 192.168.1.1)

Did 192.168.4.1/24 just become 192.168.100.1/24?

> On host:
> 
> $ ping 192.168.100.255
> PING 192.168.100.255 (192.168.100.255): 56 data bytes
> 64 bytes from 192.168.100.1: icmp_seq=0 ttl=64 time=0.245 ms
> 64 bytes from 192.168.100.1: icmp_seq=1 ttl=64 time=0.207 ms
> 64 bytes from 192.168.100.1: icmp_seq=2 ttl=64 time=0.207 ms
> ^C
> --- 192.168.100.255 ping statistics ---
> 3 packets transmitted, 3 packets received, 0% packet loss
> round-trip min/avg/max/stddev = 0.207/0.220/0.245/0.018 ms
> $ telnet 192.168.100.255 25
> Trying 192.168.100.255...
> Connected to 192.168.100.255.
> Escape character is '^]'.
> 220 my.router.local.net ESMTP Sendmail 8.11.6/8.11.2; Sat, 23 Feb 2002 14:39:21 
>+0200 (EET)

I can't reproduce this. I was only ever able to connect to the
broadcast on the local interface.

On victim "router (192.168.64.50):"

$ netstat -rn -f inet
Routing tables

Internet:
Destination        Gateway            Flags    Refs      Use  Netif Expire
default            192.168.64.254     UGSc       14     1768    dc0
127.0.0.1          127.0.0.1          UH          1   137708    lo0
172.16             link#3             UC          3        0    ep0
172.16.0.1         0:20:af:17:f:11    UHLW        0        2    lo0
192.168.64         link#1             UC          6        0    dc0
192.168.64.50      0:4:5a:40:d9:e5    UHLW       11  5310274    lo0
192.168.64.60      0:c0:f0:5a:6c:a    UHLW        4 11416791    dc0    514

On attacker "host (192.168.64.60):"

$ netstat -rn -f
Routing tables

Internet:
Destination        Gateway            Flags    Refs      Use  Netif Expire
default            192.168.64.254     UGSc        1        0    dc0
127                127.0.0.1          UGSc        0        0    lo0
127.0.0.1          127.0.0.1          UH          1     1776    lo0
172.16             192.168.64.50      UGSc        1        4    dc0
192.168.64         link#1             UC          3        0    dc0
192.168.64.50      0:4:5a:40:d9:e5    UHLW        6  1318188    dc0   1003

Now on "host,"

$ ping 172.16.0.1
PING 172.16.0.1 (172.16.0.1): 56 data bytes
64 bytes from 172.16.0.1: icmp_seq=0 ttl=64 time=0.518 ms
64 bytes from 172.16.0.1: icmp_seq=1 ttl=64 time=0.541 ms
^C
--- 172.16.0.1 ping statistics ---
2 packets transmitted, 2 packets received, 0% packet loss
round-trip min/avg/max/stddev = 0.518/0.530/0.541/0.011 ms

This works fine as expected with the weak-ES model. But for me,

$ ping 172.16.255.255
PING 172.16.255.255 (172.16.255.255): 56 data bytes
^C
--- 172.16.255.255 ping statistics ---
4 packets transmitted, 0 packets received, 100% packet loss
$ telnet 172.16.255.255
Trying 172.16.255.255...
telnet: connect to address 172.16.255.255: Operation timed out
telnet: Unable to connect to remote host

I can't reach the broadcast on the other interface. The "router" is
FreeBSD 4.5-RELEASE without any patches.

I'm not sure what I might be doing wrong.

If you are correct, and you can cross interfaces, this is a much
bigger problem. I didn't mention it in your first mail, but the
in_broadcast() function as used in the patch you sent is different
than the current implementation. in_broadacast() currently takes an
address and an interface. If you are correct, we'd have to loop
through the interface list... which makes this uglier.
-- 
Crist J. Clark                     |     [EMAIL PROTECTED]
                                   |     [EMAIL PROTECTED]
http://people.freebsd.org/~cjc/    |     [EMAIL PROTECTED]

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