How to disable IPv6 in CentOS

How to disable IPv6 in CentOS

Disable IPv6

1. problem: when using yum to download something, the system prompts that an IPv6 address is inaccessible, as shown below:

Failed [Errno 14] pycurl error 7-"Failed to connect to 2001: da8: 8000: 6023: Network is unreachable"

Trying other mirror.

Error: failure: repodata/logs from epel: [Errno 256] No more mirrors to try.

You cocould try using -- skip-broken to work around the problem

You cocould try running: rpm-Va -- nofiles -- nodigest

2. Check the NIC configuration of the Local Machine. ipv6 inet6 is indeed enabled on eth2.

[Root @ lvs05091 ~] # Ifconfig-

Eth2 Link encap: Ethernet HWaddr 00: 50: 56: A5: 2F: 9D

Inet addr: 192.168.5.91 Bcast: 192.168.5.255 Mask: 255.255.255.0

Inet6 addr: fe80 :: 250: 56ff: fea5: 2f9d/64 Scope: Link

Up broadcast running multicast mtu: 1500 Metric: 1

RX packets: 522 errors: 0 dropped: 0 overruns: 0 frame: 0

TX packets: 138 errors: 0 dropped: 0 overruns: 0 carrier: 0

Collisions: 0 FIG: 1000

RX bytes: 42263 (41.2 KiB) TX bytes: 19212 (18.7 KiB)

[Root @ lvs05091 modprobe. d] # netstat-

Active Internet connections (servers and established)

Proto Recv-Q Send-Q Local Address Foreign Address State

Tcp 0 0: 111: * LISTEN

Tcp 0 0: 22: * LISTEN

Tcp 0 0: 1: 25: * LISTEN

Tcp 0 0: 37256: * LISTEN

: IPv6

3. Disable IPv6

Modify the sysctl. conf configuration file and add the following content:

[Root @ lvs05091 etc] # vi sysctl. conf

# Shutdown IPv6

Net. ipv6.conf. all. disable_ipv6 = 1

Net. ipv6.conf. default. disable_ipv6 = 1

Is to modify the configuration to take effect

[Root @ lvs05091 etc] # sysctl-p

Restart NIC: service network restart

Note: IPv6 is permanently disabled.

It can also be disabled at zero time. IPv6 will be enabled next time.

Echo 1>/proc/sys/net/ipv6/conf/all/disable_ipv6

Echo 1>/proc/sys/net/ipv6/conf/default/disable_ipv6

4. Check the interface configuration to see that the ipv6 address is no longer in use.

[Root @ lvs05091 etc] # ifconfig-

Eth2 Link encap: Ethernet HWaddr 00: 50: 56: A5: 2F: 9D

Inet addr: 192.168.5.91 Bcast: 192.168.5.255 Mask: 255.255.255.0

Up broadcast running multicast mtu: 1500 Metric: 1

RX packets: 2336 errors: 0 dropped: 0 overruns: 0 frame: 0

TX packets: 839 errors: 0 dropped: 0 overruns: 0 carrier: 0

In this case, it is normal to use yum to download things.