DaemonForums  

Go Back   DaemonForums > OpenBSD > OpenBSD General

OpenBSD General Other questions regarding OpenBSD which do not fit in any of the categories below.

Reply
 
Thread Tools Display Modes
  #1   (View Single Post)  
Old 2nd November 2014
SlyM SlyM is offline
Port Guard
 
Join Date: Nov 2010
Posts: 21
Default 5.6 ifconfig add IPv6 address no longer adds route for whole subnet.

Hello,

Anyone know why OpenBSD 5.6 no longer adds the route for the local subnet when you plumb up a /64 address on an interface? And if this change is intentional, what is the proper route add command to add it back to where the gateway says link#2 like in the output of route show.

Thanks!
Reply With Quote
  #2   (View Single Post)  
Old 2nd November 2014
jggimi's Avatar
jggimi jggimi is offline
More noise than signal
 
Join Date: May 2008
Location: USA
Posts: 6,377
Default

As mentioned in your other thread, rtsol(8) or rtsold(8) are used to solicit routes.
Reply With Quote
  #3   (View Single Post)  
Old 2nd November 2014
SlyM SlyM is offline
Port Guard
 
Join Date: Nov 2010
Posts: 21
Default

I'm not using rtsol, I can't because I have enabled inet6 forwarding which specifically disables that functionality.

This is to manually plumb up an arbitrary address onto an interface and have it behave like IPv4 where I'd you specified a subnet mask a route to that subnet via the interface on which said IP is plumbed up on.

This used to work. Now it doesn't.
Reply With Quote
  #4   (View Single Post)  
Old 2nd November 2014
SlyM SlyM is offline
Port Guard
 
Join Date: Nov 2010
Posts: 21
Default

Here's the info from my OpenBSD router that used to route IPv6 just fine:

I have a manually assigned IPv6 address assign to the internal interface. This is an address that is obtained by another program that is unable to put the addresses in itself. So I issue an ifconfig command to plumb up the address onto the specified interface. The command is as follows:

# ifconfig $PREFIXIFACE inet6 "$PREFIX1"1 prefixlen $PREFIX1LEN

Where in this case $PREFIXIFACE is em0, $PREFIX1 is 2601:7:5780:c99:: and $PREFIX1LEN is 64.

The command mostly works as it plumbs up the requisite address onto the interface:

# ifconfig em0
em0: flags=208843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAS T,AUTOCONF6> mtu 1500
lladdr XX:XX:XX:XX:XX:XX
priority: 0
media: Ethernet autoselect (1000baseT full-duplex,master,rxpause,txpause)
status: active
inet 192.168.YY.1 netmask 0xffffff00 broadcast 192.168.YY.255
inet6 fe80::X2XX:XXff:feXX:XXXX%em0 prefixlen 64 scopeid 0x2
inet6 2601:7:5780:c99::1 prefixlen 64

However there is no route for the subnet portion of this address, merely the address itself, despite the fact that in the ifconfig output it clearly shows that it's a prefixlen of 64 which implies there are other machines that should be reachable on link within that subnet.

# netstat -nr | grep 2601
2601:7:5780:c99::1 XX:XX:XX:XX:XX:XX UHLl 0 0 - 1 lo0

But another address on the system does have the proper subnet, observe:

# netstat -nr | grep 2001
default 2001:XXXX:XXXX:XXXX::1 UGS 0 58 - 8 vr0
2001:XXXX:XXXX:XXXX::/64 link#1 UC 1 0 - 4 vr0
2001:XXXX:XXXX:XXXX::1 00:01:5c:6f:f6:46 UHLc 1 11 - 4 vr0
2001:XXXX:XXXX:XXXX:35cc:9a5e:65f7:c139 YY:YY:YY:YY:YY:YY UHLl 0 0 - 1 lo0

How do I plumb up the requisite equivalent of the line that references link#1 but of course referencing link#2?

That's what I mean...thanks!
Reply With Quote
  #5   (View Single Post)  
Old 2nd November 2014
SlyM SlyM is offline
Port Guard
 
Join Date: Nov 2010
Posts: 21
Default

Also what I'm trying to say is that previously the plumbing up of the route for the subnet I believe was handled automatically when plumbing up the address via the ifconfig command, because the subnet was implied from the prefixlen option and it was assumed that all addresses within that subnet were reachable via the same interface.
Reply With Quote
  #6   (View Single Post)  
Old 4th November 2014
SlyM SlyM is offline
Port Guard
 
Join Date: Nov 2010
Posts: 21
Default

I am not yet sure if this is a permenent solution or just a coincidence, but changing the inet6 autoconf line in my hostname.if files to say inet6 eui64 and rebooting seems to have fixed my issue.

I now have proper IPv6 routing back. Was almost ready to downgrade, only time in my life I actually considered downgrading.

Hope this helps anyone else interested in this information.
Reply With Quote
  #7   (View Single Post)  
Old 4th November 2014
jggimi's Avatar
jggimi jggimi is offline
More noise than signal
 
Join Date: May 2008
Location: USA
Posts: 6,377
Default

Congratulations!

As mentioned in my original response, eui64 was one of the possible options to enable IPv6. The autoconf option you had been using is described as "controlling whether router advertisements are accepted," and eui64 "fills the interface index automatically."

My lack of experience with IPv6 networks, other than in tunnel experiments about a decade ago, meant that I didn't -- and still don't -- clearly understand the difference.
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
With World IPv6 Launch, IPv6 on by default will be the new normal J65nko News 0 29th March 2012 07:59 PM
Username longer than 16 characters _hmp_ FreeBSD General 5 13th January 2009 10:01 AM
Two NICs on same subnet anomie Other BSD and UNIX/UNIX-like 6 7th November 2008 03:24 AM
Asking about IPv6 address berlowin Off-Topic 2 9th July 2008 02:39 AM
mpd5 stoped working after subnet change hamba FreeBSD General 0 29th May 2008 04:22 PM


All times are GMT. The time now is 10:30 PM.


Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Content copyright © 2007-2010, the authors
Daemon image copyright ©1988, Marshall Kirk McKusick