Gentoo Archives: gentoo-user

From: George Garvey <tmwg-gentoou@×××××××××××.com>
To: gentoo-user@l.g.o
Subject: [gentoo-user] [OT] Routing advice requested
Date: Sat, 16 Jul 2005 20:14:04
Message-Id: 20050716200905.GK10632@inxservices.com
1 I just installed a T1 to a new ISP using a Sangoma CSU/DSU card.
2 I thought I could use aliased IPs on existing gigE NICS on our LAN
3 to set up the hosts that need an internet routable presence.
4 Maybe that can be done, but not by me. I don't understand enough. I
5 can get it to work on the system with the T1. But not on another
6 computer over the LAN.
7
8 On the system with the T1, I have a gigE to the LAN, and one of the
9 ISP's IPs for asterisk (as an alias to the T1). That works okay. It
10 worked okay with the ISP's IP as an alias to eth0, too.
11 Edited output from ifconfig:
12 (this is the gigE NIC connected to a switch for our LAN)
13 eth0 Link encap:Ethernet HWaddr 00:07:E9:19:F3:F5
14 inet addr:192.168.1.17 Bcast:192.168.1.255 Mask:255.255.255.0
15
16 lo Link encap:Local Loopback
17 inet addr:127.0.0.1 Mask:255.0.0.0
18
19 (this is the T1. with the internet IP as an alias)
20 w1g1 Link encap:Point-to-Point Protocol
21 UP POINTOPOINT RUNNING NOARP MTU:1532 Metric:1
22 w1g1ppp Link encap:Point-to-Point Protocol
23 inet addr:209.101.232.82 P-t-P:209.101.232.81 Mask:255.255.255.252
24 UP POINTOPOINT RUNNING NOARP MTU:1500 Metric:1
25 w1g1ppp:0 Link encap:Point-to-Point Protocol
26 inet addr:216.132.251.226 P-t-P:216.132.251.226 Mask:255.255.255.224
27 UP POINTOPOINT RUNNING NOARP MTU:1500 Metric:1
28
29 (this is the routing table [route -n])
30 Destination Gateway Genmask Flags Metric Ref Use Iface
31 216.132.251.227 0.0.0.0 255.255.255.255 UH 0 0 0 eth0
32 209.101.232.80 0.0.0.0 255.255.255.252 U 0 0 0 w1g1ppp
33 216.132.251.224 0.0.0.0 255.255.255.224 U 0 0 0 w1g1ppp
34 192.168.2.0 192.168.1.12 255.255.255.0 UG 0 0 0 eth0
35 192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
36 127.0.0.0 127.0.0.1 255.0.0.0 UG 0 0 0 lo
37 0.0.0.0 209.101.232.81 0.0.0.0 UG 0 0 0 w1g1ppp
38
39 The problem I'm having is with an alias on another computer that
40 needs to be on the internet. It is the IP 216.132.251.227. Traffic
41 internal to our LAN is routed to the computer that has that alias
42 (192.168.1.6). But, traffic coming from the internet gets to 209.101.232.82
43 and stops according to traceroute.
44 I'm too ignorant to understand why the host route doesn't work for
45 packets coming from the T1 (from the internet), and get sent to the
46 computer that handles that IP. This is the latest in a series of
47 attempts. I've also tried putting the 216.132.251.224 network on the
48 LAN. I've tried using the 216.132.251.227's LAN address (192.168.1.6)
49 as a gateway for the host route. I've tried removing the
50 216.132.251.224 network route entirely, and just having host routes.
51
52 What I was hoping to do was have one computer (192.168.1.17)
53 connected to the ISP with a T1, and serve as a router for the ISP's
54 IPs. That would also be connected to the internet with one of the ISP's
55 IPs for use by asterisk (216.132.251.226). This seems to be working
56 okay.
57 I wanted another computer (192.168.1.6) to have an aliased ISP IP
58 (216.132.251.227) that would let that computer also have an internet
59 routable address. This is what I don't seem to be able to do. The
60 computer with the T1 doesn't seem to route packets from the internet
61 to the other computer over our LAN. It does for packets originating
62 from our LAN. But not for packets from the internet.
63 I know my error is going to be obvious to everyone who actually
64 understands this stuff ;) I hope I've given the info to make things
65 clear.
66 I can set up a small Fast enet switch for the ISP's network, I
67 guess. But I was hoping not to need to do that, and add more NICs to
68 the computers that eventually need to be on the internet. But maybe
69 that is what I need to do.
70 Any and all advice (including things to read to decrease my
71 ignorance) appreciated.
72 --
73 gentoo-user@g.o mailing list

Replies

Subject Author
Re: [gentoo-user] [OT] Routing advice requested David Mallwitz <dave@×××××××××.net>