Number of addresses limitation
Hi,
I'm using bridge-utils to add a bunch of tap interfaces to my computer so I can run different qemu vm at the same time without using nat to give them network access. It works fine.
But at the same time I would like to add a lot of IPv6s addresses to the bridge interface (br0). I find myself limitated to more or less 56 addresses. If I add one more, one of the addresses already existing just disappear from the br0 interface.
Is there something I could do to remove or extent this limitation ?
Best regards,
François Schmidts.
Quoted 6 lines · François Schmidts
Hi,I'm using bridge-utils to add a bunch of tap interfaces to my computer so I can run different qemu vm at the same time without using nat to give them network access. It works fine.
Quoted 6 lines
But at the same time I would like to add a lot of IPv6s addresses to the bridge interface (br0). I find myself limitated to more or less 56 addresses. If I add one more, one of the addresses already existing just disappear from the br0 interface.
Is there something I could do to remove or extent this limitation ?
Did you try the same IPv6 configuration on a normal ethernet NIC ? Do you think this is a bridge only related problem ?
Nicolas.
Quoted 8 lines
Best regards,
François Schmidts.
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Quoted 12 lines · On Wed, 25 Aug 2010 21:43:11 +0200 Nicolas de Pesloüan…
Quoted 11 lines · François Schmidts
Hi,I'm using bridge-utils to add a bunch of tap interfaces to my computer so I can run different qemu vm at the same time without using nat to give them network access. It works fine.
But at the same time I would like to add a lot of IPv6s addresses to the bridge interface (br0). I find myself limitated to more or less 56 addresses. If I add one more, one of the addresses already existing just disappear from the br0 interface.
Quoted 5 lines
Quoted 1 line
Is there something I could do to remove or extent this limitation ?
Did you try the same IPv6 configuration on a normal ethernet NIC ? Do you think this is a bridge only related problem ?
Also what tools are you using? Don't use ifconfig (iputils) for IPv6; only ip command (iproute2) works correctly with multiple addresses.
Quoted 15 lines · Stephen Hemminger
Quoted 12 lines · On Wed, 25 Aug 2010 21:43:11 +0200 Nicolas de…
Quoted 11 lines · François Schmidts
Hi,I'm using bridge-utils to add a bunch of tap interfaces to my computer so I can run different qemu vm at the same time without using nat to give them network access. It works fine.
But at the same time I would like to add a lot of IPv6s addresses to the bridge interface (br0). I find myself limitated to more or less 56 addresses. If I add one more, one of the addresses already existing just disappear from the br0 interface.
Quoted 6 lines
Quoted 4 lines
Quoted 1 line
Is there something I could do to remove or extent this limitation ?
Did you try the same IPv6 configuration on a normal ethernet NIC ? Do you think this is a bridge only related problem ?
Also what tools are you using? Don't use ifconfig (iputils) for IPv6; only ip command (iproute2) works correctly with multiple addresses.
I use something like "ip addr add <prefix>::number/64 dev br0" in a loop to add quickly multiple addresses to the bridge.
As far as I have tested it on classic interfaces like eth0, it works fine and I can see my 200 addresses (if I added 200 of them) in the output of ifconfig.
Quoted 20 lines · François Schmidts
On 25/08/2010 22:39, Stephen Hemminger wrote:Quoted 19 lines
Quoted 16 lines · On Wed, 25 Aug 2010 21:43:11 +0200 Nicolas de…
Quoted 6 lines · François Schmidts
Hi,I'm using bridge-utils to add a bunch of tap interfaces to my computer so I can run different qemu vm at the same time without using nat to give them network access. It works fine.
Quoted 6 lines
But at the same time I would like to add a lot of IPv6s addresses to the bridge interface (br0). I find myself limitated to more or less 56 addresses. If I add one more, one of the addresses already existing just disappear from the br0 interface.
Is there something I could do to remove or extent this limitation ?
Did you try the same IPv6 configuration on a normal ethernet NIC ? Do you think this is a bridge only related problem ?
Quoted 7 lines
Quoted 2 lines
Also what tools are you using? Don't use ifconfig (iputils) for IPv6; only ip command (iproute2) works correctly with multiple addresses.
I use something like "ip addr add<prefix>::number/64 dev br0" in a loop to add quickly multiple addresses to the bridge.
As far as I have tested it on classic interfaces like eth0, it works fine and I can see my 200 addresses (if I added 200 of them) in the output of ifconfig.
I just tested on a 2.6.32 kernel, and get the following results :
Whatever interface I use (bridge or normal Ethernet interface), I'm able to add 200 IPv6 address.
"ifconfig" display all the IPv6 address on the interface. "ip addr show" only display about 53 of them.
Can you try and ping the 200 IPv6 address from another host, to know whether this is a real IP problem or only a display bug. It might be an iproute2 bug on the addr show part.
Nicolas.
Quoted 31 lines · Nicolas de Pesloüan
Quoted 20 lines · François Schmidts
On 25/08/2010 22:39, Stephen Hemminger wrote:Quoted 19 lines
Quoted 16 lines · On Wed, 25 Aug 2010 21:43:11 +0200 Nicolas de…
Quoted 6 lines · François Schmidts
Hi,I'm using bridge-utils to add a bunch of tap interfaces to my computer so I can run different qemu vm at the same time without using nat to give them network access. It works fine.
Quoted 6 lines
But at the same time I would like to add a lot of IPv6s addresses to the bridge interface (br0). I find myself limitated to more or less 56 addresses. If I add one more, one of the addresses already existing just disappear from the br0 interface.
Is there something I could do to remove or extent this limitation ?
Did you try the same IPv6 configuration on a normal ethernet NIC ? Do you think this is a bridge only related problem ?
Quoted 7 lines
Quoted 2 lines
Also what tools are you using? Don't use ifconfig (iputils) for IPv6; only ip command (iproute2) works correctly with multiple addresses.
I use something like "ip addr add<prefix>::number/64 dev br0" in a loop to add quickly multiple addresses to the bridge.
As far as I have tested it on classic interfaces like eth0, it works fine and I can see my 200 addresses (if I added 200 of them) in the output of ifconfig.I just tested on a 2.6.32 kernel, and get the following results :
Quoted 7 lines
Whatever interface I use (bridge or normal Ethernet interface), I'm able to add 200 IPv6 address.
"ifconfig" display all the IPv6 address on the interface. "ip addr show" only display about 53 of them.
Can you try and ping the 200 IPv6 address from another host, to know whether this is a real IP problem or only a display bug. It might be an iproute2 bug on the addr show part.
Another test showed that one can ping the 200 addresses. So this really look like an iproute2 or netlink problem, and unrelated to bridge.
Nicolas.
Quoted 34 lines · On Thu, 26 Aug 2010 23:00:07 +0200 Nicolas de Pesloüan…
Quoted 33 lines · Nicolas de Pesloüan
Quoted 20 lines · François Schmidts
On 25/08/2010 22:39, Stephen Hemminger wrote:Quoted 19 lines
Quoted 16 lines · On Wed, 25 Aug 2010 21:43:11 +0200 Nicolas de…
Quoted 6 lines · François Schmidts
Hi,I'm using bridge-utils to add a bunch of tap interfaces to my computer so I can run different qemu vm at the same time without using nat to give them network access. It works fine.
Quoted 6 lines
But at the same time I would like to add a lot of IPv6s addresses to the bridge interface (br0). I find myself limitated to more or less 56 addresses. If I add one more, one of the addresses already existing just disappear from the br0 interface.
Is there something I could do to remove or extent this limitation ?
Did you try the same IPv6 configuration on a normal ethernet NIC ? Do you think this is a bridge only related problem ?
Quoted 7 lines
Quoted 2 lines
Also what tools are you using? Don't use ifconfig (iputils) for IPv6; only ip command (iproute2) works correctly with multiple addresses.
I use something like "ip addr add<prefix>::number/64 dev br0" in a loop to add quickly multiple addresses to the bridge.
As far as I have tested it on classic interfaces like eth0, it works fine and I can see my 200 addresses (if I added 200 of them) in the output of ifconfig.I just tested on a 2.6.32 kernel, and get the following results :
Whatever interface I use (bridge or normal Ethernet interface), I'm able to add 200 IPv6 address.
Quoted 9 lines
Quoted 5 lines
"ifconfig" display all the IPv6 address on the interface. "ip addr show" only display about 53 of them.
Can you try and ping the 200 IPv6 address from another host, to know whether this is a real IP problem or only a display bug. It might be an iproute2 bug on the addr show part.
Another test showed that one can ping the 200 addresses. So this really look like an iproute2 or netlink problem, and unrelated to bridge.
I just put 2000 addresses onto dummy device and the all show up with ip addr. Do you have old tools, the issue is likely the size of the buffer in netlink interface between ip command and kernel. Current version has 16K buffer, but it could easily be increased.
Quoted 41 lines · Stephen Hemminger
Quoted 38 lines · On Thu, 26 Aug 2010 23:00:07 +0200 Nicolas de…
Quoted 37 lines · Nicolas de Pesloüan
Quoted 20 lines · François Schmidts
On 25/08/2010 22:39, Stephen Hemminger wrote:Quoted 19 lines
Quoted 16 lines · On Wed, 25 Aug 2010 21:43:11 +0200 Nicolas de…
Quoted 6 lines · François Schmidts
Hi,I'm using bridge-utils to add a bunch of tap interfaces to my computer so I can run different qemu vm at the same time without using nat to give them network access. It works fine.
Quoted 6 lines
But at the same time I would like to add a lot of IPv6s addresses to the bridge interface (br0). I find myself limitated to more or less 56 addresses. If I add one more, one of the addresses already existing just disappear from the br0 interface.
Is there something I could do to remove or extent this limitation ?
Did you try the same IPv6 configuration on a normal ethernet NIC ? Do you think this is a bridge only related problem ?
Quoted 7 lines
Quoted 2 lines
Also what tools are you using? Don't use ifconfig (iputils) for IPv6; only ip command (iproute2) works correctly with multiple addresses.
I use something like "ip addr add<prefix>::number/64 dev br0" in a loop to add quickly multiple addresses to the bridge.
As far as I have tested it on classic interfaces like eth0, it works fine and I can see my 200 addresses (if I added 200 of them) in the output of ifconfig.I just tested on a 2.6.32 kernel, and get the following results :
Whatever interface I use (bridge or normal Ethernet interface), I'm able to add 200 IPv6 address.
"ifconfig" display all the IPv6 address on the interface. "ip addr show" only display about 53 of them.
Can you try and ping the 200 IPv6 address from another host, to know whether this is a real IP problem or only a display bug. It might be an iproute2 bug on the addr show part.
Quoted 7 lines
Quoted 3 lines
Another test showed that one can ping the 200 addresses. So this really look like an iproute2 or netlink problem, and unrelated to bridge.
I just put 2000 addresses onto dummy device and the all show up with ip addr. Do you have old tools, the issue is likely the size of the buffer in netlink interface between ip command and kernel. Current version has 16K buffer, but it could easily be increased.
Thanks for all your answers.
I tested all of this all over again and I couldn't recreate the bug, neither on my local machine or on the distant dev server I use for test and where the limitation showed up the first time. I added 2000 addresses on both which were reachable to ping without difficulties.
The problem may have come from a display bug from the tool I used then to list IP addresses.
Sorry to have bothered you with an "nonexistent" bug and thanks again.