[Routing Issue] There are two same net range routing on routing table.
Hello, We use BIRD for communication with servers with higher-level switches. But recently we came across the following case: server run as a ecmp routing. 10.171.0.0/24 proto bird nexthop via 10.171.0.25 dev p0 weight 1 nexthop via 10.171.1.25 dev p1 weight 1 For a change higher-level switches, we adjusted our ibgp LP value to flow traffic as a one path. As we expected, servers routing are changed as one path routing 10.171.0.0/24 proto bird but, one server has a two same net range routing. like this sample case1) 10.171.0.0/24 proto bird10.171.0.0/24 proto bird metric 32 nexthop via 10.171.0.25 dev ${interface1} nexthop via 10.171.1.25 dev ${interface2} case2 ) 10.171.0.0/24 proto bird metric 3210.171.0.0/24 proto bird nexthop via 10.171.0.25 dev ${interface1} nexthop via 10.171.1.25 dev ${interface2} in case1, there was any problem , but in case 2 it had. (flow packet as two paths)in my thought, pervious routing not deleted. So, two same range is now avaliable.if there are someone who have same problem, would you advise for this problem?
Hi, Do you alter krt_metric in you kernel protocol export filter? That could cause such problem. There was recently a question about it in this mailing list. Regards, Alexander On Mon, Jun 3, 2024, 03:40 이재용 <jaeyong.lee@nhn.com> wrote:
Hello,
We use BIRD for communication with servers with higher-level switches.
But recently we came across the following case:
server run as a ecmp routing.
10.171.0.0/24 proto bird nexthop via 10.171.0.25 dev p0 weight 1 nexthop via 10.171.1.25 dev p1 weight 1
For a change higher-level switches, we adjusted our ibgp LP value to flow traffic as a one path.
As we expected, servers routing are changed as one path routing
10.171.0.0/24 proto bird
but, one server has a two same net range routing. like this sample
case1)
10.171.0.0/24 proto bird
10.171.0.0/24 proto bird metric 32 nexthop via 10.171.0.25 dev ${interface1} nexthop via 10.171.1.25 dev ${interface2}
case2 )
10.171.0.0/24 proto bird metric 32
10.171.0.0/24 proto bird nexthop via 10.171.0.25 dev ${interface1} nexthop via 10.171.1.25 dev ${interface2}
in case1, there was any problem , but in case 2 it had. (flow packet as two paths)
in my thought, pervious routing not deleted.
So, two same range is now avaliable.
if there are someone who have same problem, would you advise for this problem?
Thank you for your reply. Unfortunately, There is no krt_metric in my configure. protocol kernel { persist; scan time 20; merge paths on; ipv4 {import none; export all; }; } i'm using "merge paths on" option for ecmp. is this option can be problem? -----Original Message-----From: "Alexander Zubkov" <green@qrator.net>To: "이재용" <jaeyong.lee@nhn.com>; Cc: "BIRD Users" <bird-users@network.cz>; Sent: 2024-06-03 (월) 14:17:50 (UTC+09:00)Subject: Re: [Routing Issue] There are two same net range routing on routing table.Hi, Do you alter krt_metric in you kernel protocol export filter? That could cause such problem. There was recently a question about it in this mailing list. Regards, Alexander On Mon, Jun 3, 2024, 03:40 이재용 <jaeyong.lee@nhn.com mailto:jaeyong.lee@nhn.com> wrote: Hello, We use BIRD for communication with servers with higher-level switches. But recently we came across the following case: server run as a ecmp routing. 10.171.0.0/24 http://10.171.0.0/24 proto bird nexthop via 10.171.0.25 dev p0 weight 1 nexthop via 10.171.1.25 dev p1 weight 1 For a change higher-level switches, we adjusted our ibgp LP value to flow traffic as a one path. As we expected, servers routing are changed as one path routing 10.171.0.0/24 http://10.171.0.0/24 proto bird but, one server has a two same net range routing. like this sample case1) 10.171.0.0/24 http://10.171.0.0/24 proto bird10.171.0.0/24 http://10.171.0.0/24 proto bird metric 32 nexthop via 10.171.0.25 dev ${interface1} nexthop via 10.171.1.25 dev ${interface2} case2 ) 10.171.0.0/24 http://10.171.0.0/24 proto bird metric 3210.171.0.0/24 http://10.171.0.0/24 proto bird nexthop via 10.171.0.25 dev ${interface1} nexthop via 10.171.1.25 dev ${interface2} in case1, there was any problem , but in case 2 it had. (flow packet as two paths)in my thought, pervious routing not deleted. So, two same range is now avaliable.if there are someone who have same problem, would you advise for this problem?
Hello! Which version of BIRD and Linux kernel are you running? Could you please share your configuration file and dump of `show route all`? Thanks, Maria On Mon, Jun 03, 2024 at 10:31:25AM +0900, 이재용 wrote:
Hello,
We use BIRD for communication with servers with higher-level switches.
But recently we came across the following case: server run as a ecmp routing. 10.171.0.0/24 proto bird nexthop via 10.171.0.25 dev p0 weight 1 nexthop via 10.171.1.25 dev p1 weight 1 For a change higher-level switches, we adjusted our ibgp LP value to flow traffic as a one path. As we expected, servers routing are changed as one path routing 10.171.0.0/24 proto bird but, one server has a two same net range routing. like this sample case1) 10.171.0.0/24 proto bird10.171.0.0/24 proto bird metric 32 nexthop via 10.171.0.25 dev ${interface1} nexthop via 10.171.1.25 dev ${interface2} case2 ) 10.171.0.0/24 proto bird metric 3210.171.0.0/24 proto bird nexthop via 10.171.0.25 dev ${interface1} nexthop via 10.171.1.25 dev ${interface2} in case1, there was any problem , but in case 2 it had. (flow packet as two paths)in my thought, pervious routing not deleted. So, two same range is now avaliable.if there are someone who have same problem, would you advise for this problem?
-- Maria Matejka (she/her) | BIRD Team Leader | CZ.NIC, z.s.p.o.
Hello~! i'm using bird 2.0.10 ,1.6.3. both of them have same problem. After restarting bird.service, Routing has been normalized. Because of this, I don't think I can find the phenomenon in the command you mentioned (route all) when i checked "route all" in a trouble, there was only same value shown below Detailed setting values may be problematic, so we will replace them with *. ------------- route all ---------------- BIRD 2.0.10 ready.Table master4:10.171.0.0/24 unicast [as1 2024-05-27] * (100) [********] via 10.171.0.25 on p0 Type: BGP univ BGP.origin: IGP BGP.as_path: 65200 BGP.next_hop: 10.171.51.1 BGP.local_pref: 100 unicast [as2 2024-05-27] (100) [********] via 10.171.1.25 on p1 Type: BGP univ BGP.origin: IGP BGP.as_path: 65200 BGP.next_hop: 10.171.151.1 BGP.local_pref: 50 ------------ config ------------------- log "/var/log/bird/bird.log" all;debug protocols all;protocol kernel { persist; scan time *; merge paths on; ipv4 { import none; export all; };}protocol bgp as1 { ipv4 { import all; export all; }; local *.*.*.* as *; neighbor *.*.*.* as *; direct; enable route refresh off; hold time *; error wait time *,*; capabilities on; allow bgp_local_pref; advertise hostname on;}protocol bgp as2 { ipv4 { import all; export all; }; local *.*.*.* as *; neighbor *.*.*.* as *; direct; enable route refresh off; hold time *; error wait time *,*; capabilities on; allow bgp_local_pref; advertise hostname on;} -----Original Message-----From: "Maria Matejka" maria.matejka@nic.cz mailto:maria.matejka@nic.czTo: "이재용" jaeyong.lee@nhn.com mailto:jaeyong.lee@nhn.com;Cc: bird-users@network.cz mailto:bird-users@network.cz;Sent: 2024-06-09 (일) 20:18:22 (UTC+09:00)Subject: Re: [Routing Issue] There are two same net range routing on routing table. Hello! Which version of BIRD and Linux kernel are you running? Could you please share your configuration file and dump of show route all? Thanks, Maria On Mon, Jun 03, 2024 at 10:31:25AM +0900, 이재용 wrote: > Hello, > > We use BIRD for communication with servers with higher-level switches. > > But recently we came across the following case: > server run as a ecmp routing. > 10.171.0.0/24 proto bird > nexthop via 10.171.0.25 dev p0 weight 1 > nexthop via 10.171.1.25 dev p1 weight 1 > For a change higher-level switches, we adjusted our ibgp LP value to flow traffic as a one path. As we expected, servers routing are changed as one path routing > 10.171.0.0/24 proto bird > but, one server has a two same net range routing. like this sample > case1) > 10.171.0.0/24 proto bird10.171.0.0/24 proto bird metric 32 > nexthop via 10.171.0.25 dev ${interface1} > nexthop via 10.171.1.25 dev ${interface2} > case2 ) > 10.171.0.0/24 proto bird metric 3210.171.0.0/24 proto bird > nexthop via 10.171.0.25 dev ${interface1} > nexthop via 10.171.1.25 dev ${interface2} > in case1, there was any problem , but in case 2 it had. (flow packet as two paths)in my thought, pervious routing not deleted. So, two same range is now avaliable.if there are someone who have same problem, would you advise for this problem? > – Maria Matejka (she/her) | BIRD Team Leader | CZ.NIC, z.s.p.o.
participants (3)
-
Alexander Zubkov -
Maria Matejka -
이재용