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--- wiki:centos_7_interface_naming [2017/03/09 19:54] – walkeradmin
+++ wiki:centos_7_interface_naming [2017/03/09 20:14] – walkeradmin
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 ====== CentOS 7 Interface Naming ======
+<color #db5f0b>Mar 2017</color>
+\\
+\\
+\\
+----
+<color red>Note:- </color> After reading this page, if you wish to rename your interfaces to something you are more used to, please see [[wiki:mfel_misnamed_ip_ports|this page]].
+\\
+\\
+From CentOS 7 onwards the way the interfaces are named has changed. Gone are the traditional eth0, eth1 etc. This is slightly annoying for those of use that are used to it.
+\\
+\\
+An interface name is now comprised of an identifier followed by a value for the interface.
+<sxh [txt][; options for SyntaxHighlighter]>
 Two character prefixes based on the type of interface:
 *   en -- ethernet
@@ Line 8: / Line 21: @@
 *   ww -- wwan
 *   ib -- Infiniband
 Type of names:
 *   b<number>                             -- BCMA bus core number
@@ Line 17: / Line 31: @@
                                           -- PCI geographical location
 *   [P<domain>]p<bus>s<slot>[f<function>][u<port>][..]1[i<interface>]
-                                          -- USB port number chain
+</sxh>
+\\
+Here is an example of a CentOS 7.2 installation, that is using multiple interfaces.
+\\
+<file>
+ens513f0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state DOWN qlen 1000
+ens513f1: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state DOWN qlen 1000
+ens513f2: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state DOWN qlen 1000
+ens513f3: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state DOWN qlen 1000
+enp4s0f0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP qlen 1000
+enp4s0f3: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state DOWN qlen 1000
+</file>
+\\
+So <color red>enp4s0f0</color> is what we would recognise normally as eth0.
+\\
+\\
+<color red>en</color> is Ethernet. The letters <color red>p/s</color> are the index (I have seen other letters for this) and the value <color red>enp4s0f0 etc</color> is the interface number (again, its in a crappy order that doesn't necessarily follow the hardware port numbering).
+\\
+\\
+In this above example, the server has two onboard interfaces (what we shall refer to as eth0 and eth1) and a PCI board that has four interfaces. This is why two of the interfaces have the letter p and four have the letter s. Where this letter comes from I have not yet worked out.
+\\
+\\
+<color red></color>