0

If I run ifconfig command on my rhel7 machine I see below output:

enp2s0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet x1.x2.x3.x4 netmask 255.255.255.192 broadcast xx.xx.xx.xx inet6 xxxx:xxxx:xx:xxxx::xxxx prefixlen 64 scopeid 0x0<global> lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536 inet 127.0.0.1 netmask 255.0.0.0 inet6 ::1 prefixlen 128 scopeid 0x10<host> loop txqueuelen 1000 (Local Loopback) lo:1: flags=73<UP,LOOPBACK,RUNNING> mtu 65536 inet x5.x6.x7.x8 netmask 255.255.255.255 loop txqueuelen 1000 (Local Loopback)

Edit: I read about the predictable interface naming scheme, but it nowhere mentions about the loopback interfaces below.

What does eno mean in network interface name 'eno16777736' for CentOS 7 or RHEL 7?

Interface name assignment on RHEL 7 servers

Improve this question
4
  • 1
    are you asking specifically about the "lo:1" interface? because your first link mentions "interface name 'eno...'" which could correspond to the non-loopback interface in your output (enp2s0). Commented Aug 28, 2020 at 16:59
  • yes specifically about the lo. The above link is just for reference. Yes it does mention about the eno. Just trying to understand if this naming convention is predictable, and if it will always be (at least rhel7 and rhel8) 'lo'. Commented Aug 28, 2020 at 20:00
  • Yes, the loopback interface is always called “lo”, although you’ve created another loopback interface called “lo:1” too. Commented Aug 29, 2020 at 11:52
  • nitpicking: lo:1 appears as an interface only to ifconfig because it's using the obsolete (on Linux, for networking) ioctl(2) API which has been superseded about 20 years ago in kernel 2.2 by netlink(7) socket / rtnetlink(7) API. Because on Linux the ioctl() API doesn't provide a method to add more than one IPv4 address per interface, it presents so-called alias interfaces. Any other part of the system knows only lo. eg: iptables -A INPUT -i lo:1 will never match. Forget the use of ifconfig and disregard documentation using it. Use ip link + ip address. Commented Aug 29, 2020 at 13:15

0

Reset to default

You must log in to answer this question.

Start asking to get answers

Find the answer to your question by asking.

Ask question

Explore related questions

See similar questions with these tags.