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Old 12-25-2015, 12:35 PM   #1
DeSouffle
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Registered: Aug 2012
Posts: 30

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Post When bring two interface cards, one of interface card's internet connection is lost, they are not working together


Hello everyone, I have two interface cards. First (eth0) is MosChip Semiconductor MCS7830(external USB ) , other one is Qualcomm Atheros AR8151 (internal). I have configured my interface cards correctly I think. For instance, eth0 is working. When I bring up eth1 ,one of NIC's internet connection is losing. Network Manager is disabled and I have deleted gateway from eth0. I have two router modems which are TP-LINK TD-W8951ND ,another one is DLINK 2640U. I took my configuration file is related to this is below:
cat /etc/sysconfig/network-scripts/ifcfg-eth0

DEVICE=eth0
TYPE=Ethernet
UUID=9ed309dd-4f2b-4d92-aad6-835be6fd736f
ONBOOT=no
NM_CONTROLLED=no
BOOTPROTO=none
HWADDR=00:60:6e:00:01:dd
PREFIX=24
DNS1=8.8.8.8
DEFROUTE=yes
IPV4_FAILURE_FATAL=yes
IPV6INIT=no
NAME="System eth0"
USERCTL=no
IPADDR=192.168.1.101
NETMASK=255.255.255.0
GATEWAY=192.168.1.1


cat /etc/sysconfig/network-scripts/ifcfg-eth1

DEVICE=eth1
TYPE=Ethernet
UUID=5aebfb10-8c4e-4a77-8352-61e19869d39e
ONBOOT=no
NM_CONTROLLED=no
BOOTPROTO=none
IPADDR=192.168.1.102
PREFIX=24
GATEWAY=192.168.1.1
DNS1=8.8.8.8
DEFROUTE=yes
IPV4_FAILURE_FATAL=yes
IPV6INIT=no
NAME="System eth1"
HWADDR=c8:0a:a9:3a:9f:4b
NETMASK=255.255.255.0
USERCTL=no

And this is my routing table:
[root@saytusta network-scripts]# ip route show
192.168.1.0/24 dev eth1 proto kernel scope link src 192.168.1.102
192.168.1.0/24 dev eth0 proto kernel scope link src 192.168.1.101
169.254.0.0/16 dev eth1 scope link metric 1002
169.254.0.0/16 dev eth0 scope link metric 1004
default via 192.168.1.1 dev eth1

I notice that each network card working properly , when another network card is bringed down.

Please help me as soon as you , It is urgent !

Last edited by DeSouffle; 12-25-2015 at 12:37 PM. Reason: I had have some grammatical mistakes
 
Old 12-26-2015, 07:32 AM   #2
linuxtech99
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Registered: Jan 2015
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How do you determine eth0 is not working when you bring up eth1? Also what is the status of eth0?

Quote:
ethtool eth0
Were you able to ping the gateway when eth0 down?

ping -I eth0 <gateway>

Do you see any errors related to ethernet cards in /var/log/messages?
 
Old 12-26-2015, 08:09 AM   #3
DeSouffle
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Registered: Aug 2012
Posts: 30

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Quote:
Originally Posted by linuxtech99 View Post
How do you determine eth0 is not working when you bring up eth1? Also what is the status of eth0?



Were you able to ping the gateway when eth0 down?

ping -I eth0 <gateway>

Do you see any errors related to ethernet cards in /var/log/messages?
1. Because i got static ip for each interface card, and i port forwared to this local ip from my public ip adress. WHen eth1 down, eth0 local ip and public ip works normally. Also eth1. when eth0 down, eth1 is working properly, i can ping from outside server. But when they are bringed up , one of them can not ping from outside or internet connection is losing.

2. This is status of both NICs:

Code:
# ethtool eth0
Settings for eth0:
	Supported ports: [ TP ]
	Supported link modes:   10baseT/Half 10baseT/Full 
	                        100baseT/Half 100baseT/Full 
	                        1000baseT/Half 1000baseT/Full 
	Supported pause frame use: No
	Supports auto-negotiation: Yes
	Advertised link modes:  10baseT/Half 10baseT/Full 
	                        100baseT/Half 100baseT/Full 
	                        1000baseT/Half 1000baseT/Full 
	Advertised pause frame use: Symmetric
	Advertised auto-negotiation: Yes
	Link partner advertised link modes:  10baseT/Half 10baseT/Full 
	                                     100baseT/Half 100baseT/Full 
	Link partner advertised pause frame use: Symmetric
	Link partner advertised auto-negotiation: Yes
	Speed: 100Mb/s
	Duplex: Full
	Port: Twisted Pair
	PHYAD: 1
	Transceiver: internal
	Auto-negotiation: on
	MDI-X: off
	Supports Wake-on: g
	Wake-on: g
	Current message level: 0x000000ff (255)
			       drv probe link timer ifdown ifup rx_err tx_err
	Link detected: yes
Code:
# ethtool eth1
Settings for eth1:
	Supported ports: [ TP MII ]
	Supported link modes:   10baseT/Half 10baseT/Full 
	                        100baseT/Half 100baseT/Full 
	Supported pause frame use: No
	Supports auto-negotiation: Yes
	Advertised link modes:  10baseT/Half 10baseT/Full 
	                        100baseT/Half 100baseT/Full 
	Advertised pause frame use: No
	Advertised auto-negotiation: Yes
	Link partner advertised link modes:  10baseT/Half 10baseT/Full 
	                                     100baseT/Half 100baseT/Full 
	Link partner advertised pause frame use: Symmetric
	Link partner advertised auto-negotiation: Yes
	Speed: 100Mb/s
	Duplex: Full
	Port: MII
	PHYAD: 0
	Transceiver: internal
	Auto-negotiation: on
	Current message level: 0x00000001 (1)
			       drv
	Link detected: yes
3.# ping -I eth0 192.168.1.1
PING 192.168.1.1 (192.168.1.1) from 192.168.1.4 eth0: 56(84) bytes of data.
64 bytes from 192.168.1.1: icmp_seq=1 ttl=64 time=1.40 ms
64 bytes from 192.168.1.1: icmp_seq=2 ttl=64 time=0.906 ms
64 bytes from 192.168.1.1: icmp_seq=3 ttl=64 time=0.892 ms
64 bytes from 192.168.1.1: icmp_seq=4 ttl=64 time=0.897 ms

4. Attached file is my /var/log/messages

So it means , i configured each NIC, when another turned off, another is working properly but when i bring together they are not working

Last edited by DeSouffle; 12-26-2015 at 08:11 AM.
 
Old 12-27-2015, 01:39 PM   #4
v4r3l0v
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Registered: Dec 2013
Posts: 136

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When the first card is up, do you manually try to bring up the second card?
Both of your cards are set to not turn on on boot. Try setting onboot to yes for both. Also, bootproto has to be static if you are setting IP address by yourself.

Last edited by v4r3l0v; 12-27-2015 at 01:42 PM.
 
  


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