Re: nexthost: failed to determine route to xxx.xxx.xxx.xxx

[Damian Gerow <dgerow () afflictions org>]

Thus spake kx (kxmail () gmail com) [11/04/06 23:42]:
: While there may be other issues, the only problem I can see is that
: your routing table does not provide a way for nmap to determine the
: next hop, and this is a host configuration issue, not an nmap issue.

That's exactly as I thought, but every other software package on the system
(including telnet) is able to route directly to the host in question.  I
have no problems chasing this down with the OpenBSD devs, as they were the
original intended recipients of this.

: At the least, please add a specific route for the target network, and
: it is probably best to add a default gateway. I believe the route
: command on OpenBSD and FreeBSD is mostly the same so try:

There /is/ a default route, as provided by the in-kernel PPPoE stuffs.
Here's my routing table:

    Internet:
    Destination        Gateway            Flags     Refs     Use    Mtu Interface
    default            0.0.0.1            UGS        11  2057548      - pppoe0
    0.0.0.1            0.0.0.0            UH          1        0      - pppoe0
    10.0.0.0/30        link#1             UC          0        0      - vr0
    10.9.22/24         link#4             UC          1        0      - fxp1
    127/8              127.0.0.1          UGRS        0        0  33224 lo0
    127.0.0.1          127.0.0.1          UH          3      549  33224 lo0
    172.19.206/24      link#2             UC          4        0      - fxp0
    192.168.132/24     link#3             UC          0        0      - ral0
    224/4              127.0.0.1          URS         0        0  33224 lo0

Note the 'default' entry.

nmap is perfectly able to route to non-directly-connected hosts (i.e. hosts
that require the use of the default gateway) so long as I don't force it to
try to use raw packets:

    # nmap -sT -P0 -p 80 www.google.ca

    Starting Nmap 4.01 ( http://www.insecure.org/nmap/ ) at 2006-04-11 23:39 EDT
    Interesting ports on 64.233.167.99:
    PORT   STATE SERVICE
    80/tcp open  http

    Nmap finished: 1 IP address (1 host up) scanned in 0.367 seconds
    # nmap -sS -P0 -p 80 www.google.ca 

    Starting Nmap 4.01 ( http://www.insecure.org/nmap/ ) at 2006-04-11 23:39 EDT
    WARNING: Unable to find appropriate interface for system route to 0.0.0.1

    WARNING: Unable to find appropriate interface for system route to 0.0.0.0

    nexthost: failed to determine route to 64.233.167.147
    QUITTING!
    # 

: If this does not remedy the solution, please let myself and the list know.

I can't add a default route, as one is already there.  And if I change it to
be the actual next-hop (instead of the 0.0.0.1 representation), then
networking itself breaks on the box.

  - Damian


_______________________________________________
Sent through the nmap-dev mailing list
http://cgi.insecure.org/mailman/listinfo/nmap-dev