LinuxQuestions.org
Share your knowledge at the LQ Wiki.
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Server
User Name
Password
Linux - Server This forum is for the discussion of Linux Software used in a server related context.

Notices


Reply
  Search this Thread
Old 05-15-2008, 07:18 AM   #1
neocontrol
Member
 
Registered: Jul 2005
Posts: 273

Rep: Reputation: 31
Maybe a routing problem? 5 differnt IP blocks, only 1 works


Hi,

What I have going on is that we have 5 new IP blocks, with the main differences being 2 different subnets between my original and new ips. 255.255.255.224 and 255.255.255.248.

What is working is my original ip range we started with. But everything I have added (21 new ones) does not work. I can ping them locally, but I can not go out of them, I cannon come in on any of them. I know it's not a firewall issue as I have tried getting in / out with it off.

Lets say I have these new networks,

66.12.123.0
205.34.58.0
104.44.65.0
66.12.124.0
104.44.66.0

I have the ifcfg's looking like this, with the proper details of course.

Device=eth0:X
OnBoot=yes
BOOTPROTO=static
IPADDR=x.x.x.x
Netmask=255.255.255.x
network=x.x.x.0
gateway=x.x.x.x

When I do a 'route'. It looks to me as if they are all going out (or trying to) of the same default gateway. I'm ultimately pretty lost when it comes to this route stuff so if someone can point me to a good how to, or just explain it well, I'd appreciate it. Or maybe I'm way off here.

Here's an example of my route. Obviously the numbers have been changed to protect the innocent.

Destination Gateway Genmask Flags Metric Ref Use Iface
66.12.123.0 * 255.255.255.248 U 0 0 0 eth0
205.34.58.0 * 255.255.255.248 U 0 0 0 eth0
104.44.65.0 * 255.255.255.248 U 0 0 0 eth0
66.12.124.0 * 255.255.255.248 U 0 0 0 eth0
205.67.44.0 * 255.255.255.228 U 0 0 0 eth0
222.22.22.0 * 255.255.255.224 U 0 0 0 eth0
10.1.1.0 * 255.255.255.0 U 0 0 0 eth1
169.254.0.0 * 255.255.0.0 U 0 0 0 eth0
default my.firewall 0.0.0.0 UG 0 0 0 eth0

Can you guys help my newbie looking ways?
 
Old 05-15-2008, 12:18 PM   #2
dkm999
Member
 
Registered: Nov 2006
Location: Seattle, WA
Distribution: Fedora
Posts: 407

Rep: Reputation: 35
It would be illuminating to see what ifconfig reports about all these (virtual) interfaces. There could be some trouble lurking in the actual configuration of those interfaces, as distinct from what you have written in the config files.

The default route is correct; you can only have one per system, since its purpose is to direct traffic that the machine otherwise does not know how to route. If you want something else (eg, to send traffic destined for a particular subnet out a different interface) you need to install a static route for that net.

If these points do not shed any light on your problem, I recommend using tcpdump to watch what happens when you attempt to use one of the address ranges that "does not work". A good starter command is
Code:
#tcpdump -i any -nn net 66.12.123.0/29
This will capture packets coming from or going to any address in the 66.12.123.0 subnet on any interface. RTFM for details of the multitude of switches and packet-matching options that tcpdump offers.

BTW, when you change the reported results, that introduces an uncertainty in the diagnosis, because you might have just obscured an actual discrepancy that will lead to a resolution of your problem. Your "security by obscurity" approach doesn't actually do you much good, either, because the bad guys on the Internet are not harvesting IP addresses from blogs like this; they are doing broad coverage searches using botnets to find weakly defended systems.
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off



Similar Threads
Thread Thread Starter Forum Replies Last Post
problem bad-blocks to install emamarro Linux - Hardware 1 04-12-2007 12:29 AM
Xerox 8400 DP and differnt distros. kvtournh Linux - Hardware 0 04-20-2004 04:22 AM
Differnt kinds of Linux satusred Linux - Software 6 11-02-2003 04:59 PM
Starting differnt window managers durden2.0 Linux - Newbie 2 06-02-2003 08:41 PM
problem in getting free data blocks in filesystem udayan Programming 4 07-07-2002 01:03 AM

LinuxQuestions.org > Forums > Linux Forums > Linux - Server

All times are GMT -5. The time now is 12:44 PM.

Main Menu
Advertisement
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration