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Bug 602368

Summary: Downing a single IP aliased eth interface leads to multiple interfaces downed
Product: Red Hat Enterprise Linux 5 Reporter: Jason Strobush <jason>
Component: net-toolsAssignee: Jiri Popelka <jpopelka>
Status: CLOSED NOTABUG QA Contact: qe-baseos-daemons
Severity: medium Docs Contact:
Priority: low    
Version: 5.4CC: fge
Target Milestone: rc   
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2010-06-10 15:22:54 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description Jason Strobush 2010-06-09 17:39:45 UTC 
Description of problem:

Downing eth0:1, for example, can lead to all eth0:x devices that share the subnet to be removed

Version-Release number of selected component (if applicable):


How reproducible: 100%


Steps to Reproduce:
1.  CentOS 5.4 x64 host, running in VMWare Workstation 7, running 2.6.18-164.el5. The host has four physical network cards, but only one is bound and active; eth0, which is 192.168.10.1 

Adding additional IP aliases to eth0, as shown, works correctly: 

ifconfig eth0:3 192.168.17.170 
ifconfig eth0:8 192.168.17.150 
ifconfig eth0:9 192.168.17.190 

However, when issuing the reverse, "ifconfig eth0:3 down", all three addresses and IP aliased eth0:x interfaces are removed from the system

Expected results:

Only requested interface to be removed.
Additional info:
Comment 1 Jiri Popelka 2010-06-10 10:03:06 UTC 
Works for me.

[root@dhcp-29-33]# ifconfig eth1:1 192.168.17.110 netmask 255.255.0.0 up
[root@dhcp-29-33]# ifconfig eth1:3 192.168.17.130 netmask 255.255.0.0 up
[root@dhcp-29-33]# ifconfig eth1:8 192.168.17.180 netmask 255.255.0.0 up
[root@dhcp-29-33]# ifconfig eth1:9 192.168.17.190 netmask 255.255.0.0 up
[root@dhcp-29-33]# ifconfig -a
eth1      Link encap:Ethernet  HWaddr 08:00:27:BA:DC:CF  
          inet addr:192.168.10.1  Bcast:192.168.255.255  Mask:255.255.0.0
          inet6 addr: fe80::a00:27ff:feba:dccf/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:31 errors:0 dropped:0 overruns:0 frame:0
          TX packets:541 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:4239 (4.1 KiB)  TX bytes:88294 (86.2 KiB)
          Interrupt:9 Base address:0xd060 

eth1:1    Link encap:Ethernet  HWaddr 08:00:27:BA:DC:CF  
          inet addr:192.168.17.110  Bcast:192.168.255.255  Mask:255.255.0.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          Interrupt:9 Base address:0xd060 

eth1:3    Link encap:Ethernet  HWaddr 08:00:27:BA:DC:CF  
          inet addr:192.168.17.130  Bcast:192.168.255.255  Mask:255.255.0.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          Interrupt:9 Base address:0xd060 

eth1:8    Link encap:Ethernet  HWaddr 08:00:27:BA:DC:CF  
          inet addr:192.168.17.180  Bcast:192.168.255.255  Mask:255.255.0.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          Interrupt:9 Base address:0xd060 

eth1:9    Link encap:Ethernet  HWaddr 08:00:27:BA:DC:CF  
          inet addr:192.168.17.190  Bcast:192.168.255.255  Mask:255.255.0.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          Interrupt:9 Base address:0xd060 
[root@dhcp-29-33]# ip a
3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000
    link/ether 08:00:27:ba:dc:cf brd ff:ff:ff:ff:ff:ff
    inet 192.168.10.1/16 brd 192.168.255.255 scope global eth1
    inet 192.168.17.110/16 brd 192.168.255.255 scope global secondary eth1:1
    inet 192.168.17.130/16 brd 192.168.255.255 scope global secondary eth1:3
    inet 192.168.17.180/16 brd 192.168.255.255 scope global secondary eth1:8
    inet 192.168.17.190/16 brd 192.168.255.255 scope global secondary eth1:9
    inet6 fe80::a00:27ff:feba:dccf/64 scope link 
       valid_lft forever preferred_lft forever
[root@dhcp-29-33]# ifconfig eth1:3 down
[root@dhcp-29-33]# ifconfig -a
eth1      Link encap:Ethernet  HWaddr 08:00:27:BA:DC:CF  
          inet addr:192.168.10.1  Bcast:192.168.255.255  Mask:255.255.0.0
          inet6 addr: fe80::a00:27ff:feba:dccf/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:31 errors:0 dropped:0 overruns:0 frame:0
          TX packets:542 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:4239 (4.1 KiB)  TX bytes:88421 (86.3 KiB)
          Interrupt:9 Base address:0xd060 

eth1:1    Link encap:Ethernet  HWaddr 08:00:27:BA:DC:CF  
          inet addr:192.168.17.110  Bcast:192.168.255.255  Mask:255.255.0.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          Interrupt:9 Base address:0xd060 

eth1:8    Link encap:Ethernet  HWaddr 08:00:27:BA:DC:CF  
          inet addr:192.168.17.180  Bcast:192.168.255.255  Mask:255.255.0.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          Interrupt:9 Base address:0xd060 

eth1:9    Link encap:Ethernet  HWaddr 08:00:27:BA:DC:CF  
          inet addr:192.168.17.190  Bcast:192.168.255.255  Mask:255.255.0.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          Interrupt:9 Base address:0xd060
[root@dhcp-29-33]# ip a
3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000
    link/ether 08:00:27:ba:dc:cf brd ff:ff:ff:ff:ff:ff
    inet 192.168.10.1/16 brd 192.168.255.255 scope global eth1
    inet 192.168.17.110/16 brd 192.168.255.255 scope global secondary eth1:1
    inet 192.168.17.180/16 brd 192.168.255.255 scope global secondary eth1:8
    inet 192.168.17.190/16 brd 192.168.255.255 scope global secondary eth1:9
    inet6 fe80::a00:27ff:feba:dccf/64 scope link 
       valid_lft forever preferred_lft forever
Comment 2 Jason Strobush 2010-06-10 14:01:06 UTC 
The errored behavior only appears when eth0:x is used.  Other interfaces tested (eth1 through 3) worked without issue.
Comment 3 Jiri Popelka 2010-06-10 14:33:03 UTC 
Interface doesn't matter. I guess I know what's going on here.
Please show me what 'ip a' command does when you add all the aliases.
Comment 4 Jason Strobush 2010-06-10 15:03:16 UTC 
Jiri -

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000
    link/ether 00:0c:29:1c:29:d8 brd ff:ff:ff:ff:ff:ff
    inet 192.168.10.1/24 brd 192.168.10.255 scope global eth0
    inet 192.168.17.170/24 brd 192.168.17.255 scope global eth0:3
    inet 192.168.17.150/24 brd 192.168.17.255 scope global secondary eth0:8
    inet 192.168.17.190/24 brd 192.168.17.255 scope global secondary eth0:9
    inet6 fe80::20c:29ff:fe1c:29d8/64 scope link
       valid_lft forever preferred_lft forever
3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000
    link/ether 00:0c:29:1c:29:e2 brd ff:ff:ff:ff:ff:ff
    inet 192.168.11.1/24 brd 192.168.11.255 scope global eth1
    inet6 fe80::20c:29ff:fe1c:29e2/64 scope link
       valid_lft forever preferred_lft forever
4: eth2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000
    link/ether 00:0c:29:1c:29:ec brd ff:ff:ff:ff:ff:ff
    inet 172.31.246.9/16 brd 172.31.255.255 scope global eth2
    inet6 2001:a9fe:3100:10:20c:29ff:fe1c:29ec/64 scope global dynamic
       valid_lft 2591890sec preferred_lft 604690sec
    inet6 2001:a9fe:3100:1:20c:29ff:fe1c:29ec/64 scope global dynamic
       valid_lft 2591890sec preferred_lft 604690sec
    inet6 fe80::20c:29ff:fe1c:29ec/64 scope link
       valid_lft forever preferred_lft forever
5: eth3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000
    link/ether 00:0c:29:1c:29:f6 brd ff:ff:ff:ff:ff:ff
    inet 192.168.17.166/24 brd 192.168.17.255 scope global eth3
    inet6 fe80::20c:29ff:fe1c:29f6/64 scope link
       valid_lft forever preferred_lft forever
6: sit0: <NOARP> mtu 1480 qdisc noop
    link/sit 0.0.0.0 brd 0.0.0.0
Comment 5 Jiri Popelka 2010-06-10 15:22:54 UTC 
Thanks Jason,
let's finish this :-)

When you look at the eth0 section
    inet 192.168.10.1/24 brd 192.168.10.255 scope global eth0
    inet 192.168.17.170/24 brd 192.168.17.255 scope global eth0:3
    inet 192.168.17.150/24 brd 192.168.17.255 scope global secondary eth0:8
    inet 192.168.17.190/24 brd 192.168.17.255 scope global secondary eth0:9
you can see that some addresses are marked secondary and some not. If you look (http://linux-ip.net/gl/ip-cref/node33.html) at what secondary means:
" 
An IP address becomes secondary if another address with the same prefix bits already exists. The first address is primary. It is the leader of the group of all secondary addresses. When the leader is deleted, all secondaries are purged too. 
"

So, what you do is that you add address (alias eth0:3)
with different prefix (192.168.17.0/24)
than the first one has (192.168.10.0/24).
That creates primary address.
When you add other aliases with the same prefix (192.168.17.0/24),
secondary addresses are created.
When you then delete (try it please) one of the secondaries (eth0:8 or eth0:9) only this address gets removed.
But when you delete the primary (eth0:3) all secondaries are purged too.

In my case it was OK, because I used the same prefix in all cases,
so only secondaries were created in my case.
I used /16 netmask so 192.168.10.1/16 and 192.168.17.110/16 have the same prefix (192.168.0.0/16).

I hope this clarifies it.

I encourage you to learn and use ip command
instead of ifconfig (it is obsolete).
With ip command you can do the same (and more)
as with ifconfig, but it's much more
suitable for current linux kernels.

With ip you can add address (alias):
ip addr add 192.168.17.170/24 brd + dev eth0 label eth0:3
And delete address (alias):
ip addr del 192.168.17.170/24 dev eth0

See
http://linux-ip.net/gl/ip-cref/
Comment 7 Jiri Popelka 2011-03-04 14:23:38 UTC 
*** Bug 682147 has been marked as a duplicate of this bug. ***