Visit The New, Modern Unix Linux Community

Lan card not reaching Gateway

Thread Tools Search this Thread
Operating Systems Linux Lan card not reaching Gateway
# 1  
Lan card not reaching Gateway


I have this problem on RHEL box. I am using two NIC's of same model and make (Intel 82557) in the adjacent PCI slots . I am using each one for different subnet and have assigned them ipaddresses and gateways of respective subnets . While one is O.K. connecting to its gateway other don't. I have checked this card in Winows and its working fine. Card is not faulty. Problem only starts in RHEL.

ip1 -----> gateway
ip2 --X--> gateway

Any help is aprreciated.


# 2  
What is the output of
 netstat -nr

# 3  
Linux as router


I have two subnets (, and a RH linux box. I know linux can act as router, but specifically want to ask if this acts as a router without any route addition on all nodes of two subnets. I mean , I need Not to add anything at each of the subnet nodes (obviously gateway is there) but only add routes in the linux box. I have checked enabling ip forwarding in files /etc/syscntl.conf and /proc/sys/net/ipv4/ip_forward. But that donot make any difference . I am unable to ping the node of 2nd subnet with the node of 1st subnet. My linux box has two nic's with and (node s1) ---->, <---- (node s2)

Firstly, is it achievable that by only adding routes on linux box I can make two subnets communicate. If yes then what route I need to put on this. (I donot want to add any route on the subnet nodes except the subnet gateway - and

Thanks in advance ,

# 4  
Try turning off the firewall on the RH box.
service iptables stop

And check that /proc/sys/net/ipv4/ip_forward has a value of 1.
# 5  
I have merged these two threads as they relate to the same problem.
# 6  

Firstly they do not point to same problem . First problem was that my node on one subnet was unable to connect to its gateway. BTW it is resolved now . May be some stucking at the network switch point was there. As I rebooted, it got OK.

My second post was one subnet not connecting to other with all ip forwarding done at the linux box connecting these.As you gave reply to stop firewall, I did that. But same status.

I am only able to reach the first subnet's gateway from the node in second subnet but this also bu putting route at node itself which I did not want. I am not getting what is going wrong. All posts I read on internet say these simple steps to make subnets communicate and I am doing them all, but still both subnets are unable to communicate .

/etc/sysctl.conf , ip-forwading = 1
sysctl -p
/sys/proc/net/ipv4/ip-forward, = 1
Firewall disabled

(From linux box , I am able to connect to nodes of both subnets.) (node s1) ---->, <---- (node s2)

node donot communicate with (and so

Any more suggestions ?

Thanks in advance


---------- Post updated at 03:52 PM ---------- Previous update was at 03:50 PM ----------


It is : (node s1) ---->, ----------------------------
-------------------------- <---- (node s2)

subnet node 1 linux box subnet node 2


Previous Thread | Next Thread
Thread Tools Search this Thread
Search this Thread:
Advanced Search

Test Your Knowledge in Computers #188
Difficulty: Easy
Python is an interpreted, high-level, general-purpose programming language, created by Linus Torvalds and first released in 1991
True or False?

10 More Discussions You Might Find Interesting

1. UNIX for Beginners Questions & Answers

Inconsistency between RedHat 6.5 global gateway and single gateway leads to loss of default gateway

Dear friends I use RedHat 6.5, which sets the gateway in the configuration file / etc / sysconfig / network as GATEWAY =, and the gateway in the configuration file / etc / sysconfig / network-scripts / ifcfg-eth11 as GATEWAY = The two gateways are different.... (6 Replies)
Discussion started by: tanpeng
6 Replies

2. Red Hat

PC cannot reach two lan card Linux box

we have red hat 6 linux box There are two lan card one lan card eth0 have ip GW 2th lan card eth1 have ip GW I have below route ... I use two route table root@xxx# netstat -rn Kernel IP routing table Destination Gateway ... (5 Replies)
Discussion started by: chuikingman
5 Replies

3. Solaris

Can't ping new PCI LAN card x4270_m2

Hi, I've recently moved my pci LAN card from Slot2 Slot5 on my sun x4270_m2 server (solaris 10). I've done the touch / reconfigure and devfsadm, however my issue is that im able to configure the e1000g7 port with an ip address ( but if i plug my laptop (set with static ip... (7 Replies)
Discussion started by: kerrygold
7 Replies

4. Linux

How to check the LAN card?

Hi. I have a lan card installed on my server. I want to check the duplex speed of it. How can I check it? Help is appreciated. Thank you. (3 Replies)
Discussion started by: Amol21
3 Replies

5. Programming

LAN card status Information

Please tell me API in Solaris / Linux / UNIX to get status information of LAN card. (1 Reply)
Discussion started by: mansoorulhaq
1 Replies

6. SCO

lan card not detecting

hi all i have installed SCO 5.0.5 on a "Netfinity 5000" IBM server. But the OS is not detecting the lan card. how can i detect it.... help and thanks in advance . bidhayak (3 Replies)
Discussion started by: bidhayakm
3 Replies

7. Solaris

Does x86 solaris 9 support PCI RealTek Lan Card

Hi, i have a RealTek Lan Card on my machine. Does Solaris 9 supports this lan card . Thank You, Shafi (3 Replies)
Discussion started by: sol8admin
3 Replies

8. SCO

LAN card problem

Dear all Im facing one problem in SCO 5.0.5 , its that in the server there are three LAN cards INTEL PRO 100 series but when we configure all the three cards then LAN stops working . self ping is possible but no one can ping the server. If we remove driver of any one card LAN starts working. Is... (1 Reply)
Discussion started by: ccvyas
1 Replies

9. Cybersecurity

lan card autonegotiation?

what is lan card autonegotiation ? how to enable and disable this feature? (2 Replies)
Discussion started by: nabil_boussetta
2 Replies

10. UNIX for Advanced & Expert Users

LAN Card Problem !

The Lan card in one of our UIII WS's seem doesn't work,so with ping command i can not see any of the machines in LAN and with some other tests i'm sure it's not OK. I tried to use the second card on PCI port ,but the replaced card was one of the ordinary card for PC's the way after... (1 Reply)
Discussion started by: nikk
1 Replies

Featured Tech Videos