RedHatEnterpriseLinux5.X Solution

Environment: RedHatEnterpriseLinux5.X symptom: Use the ifconfig command to view the NIC information and find redundant information such as virbr0 and xenbr0, as shown below: [root @ EXFO ~] # Ifconfigeth0Linkencap: EthernetHWaddr00: 0C: 29: 64: C4: 80

Environment: RedHat Enterprise Linux 5.X

Symptom:

Run the ifconfig command to view the NIC information and find redundant information such as virbr0 and xenbr0, as shown below:

[Root @ EXFO ~] # Ifconfig
Eth0 Link encap: Ethernet HWaddr 00: 0C: 29: 64: C4: 80
Inet addr: XXX. XX Bcast: XXX. XX Mask: Invalid bandwidth limit 192
Inet6 addr: fe80: 20c: 29ff: fe64: c480/64 Scope: Link
Up broadcast running multicast mtu: 1500 Metric: 1
RX packets: 4510 errors: 0 dropped: 0 overruns: 0 frame: 0
TX packets: 300 errors: 0 dropped: 0 overruns: 0 carrier: 0
Collisions: 0 txqueuelen: 0
RX bytes: 281040 (274.4 KiB) TX bytes: 26056 (25.4 KiB)

Eth1 Link encap: Ethernet HWaddr 00: 0C: 29: 64: C4: 8A
Inet addr: 192.216.6.78 Bcast: 192.216.6.255 Mask: 255.255.255.0
Inet6 addr: fe80: 20c: 29ff: fe64: c48a/64 Scope: Link
Up broadcast running multicast mtu: 1500 Metric: 1
RX packets: 1201 errors: 0 dropped: 0 overruns: 0 frame: 0
TX packets: 421 errors: 0 dropped: 0 overruns: 0 carrier: 0
Collisions: 0 FIG: 1000
RX bytes: 80721 (78.8 KiB) TX bytes: 93549 (91.3 KiB)
Base address: 0x1078 Memory: f4840000-f4860000

Lo Link encap: Local Loopback
Inet addr: 127.0.0.1 Mask: 255.0.0.0
Inet6 addr: 1/128 Scope: Host
Up loopback running mtu: 16436 Metric: 1
RX packets: 1664 errors: 0 dropped: 0 overruns: 0 frame: 0
TX packets: 1664 errors: 0 dropped: 0 overruns: 0 carrier: 0
Collisions: 0 txqueuelen: 0
RX bytes: 2460982 (2.3 MiB) TX bytes: 2460982 (2.3 MiB)

Peth0 Link encap: Ethernet HWaddr FE: FF
Inet6 addr: fe80: fcff: ffff: feff: ffff/64 Scope: Link
Up broadcast running noarp mtu: 1500 Metric: 1
RX packets: 6152 errors: 0 dropped: 0 overruns: 0 frame: 0
TX packets: 376 errors: 0 dropped: 0 overruns: 0 carrier: 0
Collisions: 0 FIG: 1000
RX bytes: 384572 (375.5 KiB) TX bytes: 44157 (43.1 KiB)
Base address: 0x1070 Memory: f4820000-f4840000

Vif0.0 Link encap: Ethernet HWaddr FE: FF
Inet6 addr: fe80: fcff: ffff: feff: ffff/64 Scope: Link
Up broadcast running noarp mtu: 1500 Metric: 1
RX packets: 332 errors: 0 dropped: 0 overruns: 0 frame: 0
TX packets: 5989 errors: 0 dropped: 0 overruns: 0 carrier: 0
Collisions: 0 txqueuelen: 0
RX bytes: 36048 (35.2 KiB) TX bytes: 372384 (363.6 KiB)

Virbr0 Link encap: Ethernet HWaddr 00: 00: 00: 00: 00: 00
Inet addr: 192.168.122.1 Bcast: 192.168.122.255 Mask: 255.255.255.0
Inet6 addr: fe80: 200: ff: fe00: 0/64 Scope: Link
Up broadcast running multicast mtu: 1500 Metric: 1
RX packets: 0 errors: 0 dropped: 0 overruns: 0 frame: 0
TX packets: 53 errors: 0 dropped: 0 overruns: 0 carrier: 0
Collisions: 0 txqueuelen: 0
RX bytes: 0 (0.0 B) TX bytes: 10188 (9.9 KiB)

Xenbr0 Link encap: Ethernet HWaddr FE: FF
Up broadcast running noarp mtu: 1500 Metric: 1
RX packets: 6158 errors: 0 dropped: 0 overruns: 0 frame: 0
TX packets: 0 errors: 0 dropped: 0 overruns: 0 carrier: 0
Collisions: 0 txqueuelen: 0
RX bytes: 311095 (303.8 KiB) TX bytes: 0 (0.0 B)

Solution:

If you suspect that these redundant configuration conflicts cause the service to fail to connect to the network, try to delete unnecessary information such as virbr0 and xenbr0, that is, vi/boot/grub. change default = 0 to default = 1 in conf, save and exit, and the reboot server can solve the problem.

 

Then, use ifconfig to view the following information:

[Root @ EXFO ~] # Ifconfig
Eth0 Link encap: Ethernet HWaddr 00: 0C: 29: 64: C4: 80
Inet addr: XXX. XX Bcast: XXX. XX Mask: Invalid bandwidth limit 192
Inet6 addr: fe80: 20c: 29ff: fe64: c480/64 Scope: Link
Up broadcast running multicast mtu: 1500 Metric: 1
RX packets: 1172206 errors: 0 dropped: 0 overruns: 0 frame: 0
TX packets: 75628 errors: 0 dropped: 0 overruns: 0 carrier: 0
Collisions: 0 FIG: 1000
RX bytes: 93410582 (89.0 MiB) TX bytes: 28185193 (26.8 MiB)
Base address: 0x1070 Memory: f4820000-f4840000

Eth1 Link encap: Ethernet HWaddr 00: 0C: 29: 64: C4: 8A
Inet addr: 192.216.6.78 Bcast: 192.216.6.255 Mask: 255.255.255.0
Inet6 addr: fe80: 20c: 29ff: fe64: c48a/64 Scope: Link
Up broadcast running multicast mtu: 1500 Metric: 1
RX packets: 5172160 errors: 0 dropped: 0 overruns: 0 frame: 0
TX packets: 2407634 errors: 0 dropped: 0 overruns: 0 carrier: 0
Collisions: 0 FIG: 1000
RX bytes: 4108624765 (3.8 GiB) TX bytes: 139136852 (132.6 MiB)
Base address: 0x1078 Memory: f4840000-f4860000

Lo Link encap: Local Loopback
Inet addr: 127.0.0.1 Mask: 255.0.0.0
Inet6 addr: 1/128 Scope: Host
Up loopback running mtu: 16436 Metric: 1
RX packets: 1182 errors: 0 dropped: 0 overruns: 0 frame: 0
TX packets: 1182 errors: 0 dropped: 0 overruns: 0 carrier: 0
Collisions: 0 txqueuelen: 0
RX bytes: 1823252 (1.7 MiB) TX bytes: 1823252 (1.7 MiB)

[Root @ EXFO ~] #
Excess information such as virbr0 and xenbr0 has disappeared, and the server can access the Internet.