Or maybe you want to set the source IP based on some external information (for
example what provider you received the default route from)?
Yes, maybe this one.
On Thu, November 21 2024 at 12:40 AM Alexander Zubkov
<[email protected]> wrote:
It is still unclear what you want to achive. Do you want Linux to use
both IPs as src at once in ECMP-like manner? Or maybe you want to set the
source IP based on some external information (for example what provider you
received the default route from)? Something else?
On Wed, Nov 20, 2024 at 11:06 AM hans.heng <[email protected]> wrote:
I just think now these two VIP are unequal, because default routing will use
38.145.72.193 instead of 38.145.72.198… No actual problem now, just a question
and can we achieve this?
On Wed, November 20 2024 at 6:00 PM Alexander Zubkov
<[email protected]> wrote:
And what is you intention then? You want to use both sources at once
in ecmp-like manner, when the server makes a connection? Or something else?
On Wed, Nov 20, 2024, 10:44 hans.heng <[email protected]> wrote:
You can set krt_prefsrc in bird. If I remember the option name right.
But we have already this for the first virtual ip 38.145.72.193, I do not know
how to additionally add routing I mentioned in the previoius thread for the
second virtual ip 38.145.72.198.protocol kernel {
scan time 1;
merge paths yes limit 4;
ipv4 {
import none;
export filter {
if proto = direct1 then reject;
krt_prefsrc = 38.145.72.193;
accept;
};
};
}
Thanks,
Hans
On Wed, November 20 2024 at 5:40 PM Alexander Zubkov
<[email protected]> wrote:
You can set krt_prefsrc in bird. If I remember the option name right.
On Wed, Nov 20, 2024, 10:11 hans.heng <[email protected]> wrote:
> Hi Hans,
>
> What about just adding it to your LOCAL_NET list? If it works for the first
> IP, why it shouldn't work for the other?
Hi Alexander,
You’re right, simply adding it to LOCAL_NET list does work, other hosts then
can test tcp stream on this new virtual ip.
But what confused me is that how can we add export a routing rule like this:
$ ip route
default proto bird src 38.145.72.193 metric 32
nexthop via 10.105.1.10 dev enp4s0f0 weight 1
nexthop via 10.105.1.12 dev enp4s0f1 weight 1
Namely, how this server sends out the traffic using new virtual ip
38.145.72.198 as source addr?
Thanks,
Hans
On Wed, November 20 2024 at 4:03 PM Alexander Zubkov
<[email protected]> wrote:
Hi Hans,
What about just adding it to your LOCAL_NET list? If it works for the first IP,
why it shouldn't work for the other?
On Wed, Nov 20, 2024 at 8:36 AM Hans Heng via Bird-users
<[email protected]> wrote:
Hi all!
I have a dual-home server, whose connection topology and configuration is
described as below.
**** Connection Topology and Configuration ****
The server has two physical NICs enp4s0f0 and enp4s0f1, which are connected to
two separate ports TOR_A and TOR_B on a Top of Rack (TOR) router, each
representing a separate BGP session through bgp_A and bgp_B protocol.
The server also has a dummy interface named em5, which has a private ip
38.145.72.193/32.
Bird kernel protocol exports an ECMP routing rule to kernel as a kernel default
routing, and bgp_A/bgp_B protocol export the private ip to my internet, then
38.145.72.193/32 on em5 acts as a public ip.
**** My goal ****
I want to add another virtual ip on em5, say 38.145.72.198/32, and let this new
virtual ip act as a public ip too.
Can this requirement be met? If yes, how should I modify the configuration to
make BGP advertise this ip over my internet?
**** Additional Information on Server ****
## bird setup an ECMP route on 2 phy nics as default route,
## which set source ip to the public ip
$ ip route
default proto bird src 38.145.72.193 metric 32
nexthop via 10.105.1.10 dev enp4s0f0 weight 1
nexthop via 10.105.1.12 dev enp4s0f1 weight 1
10.105.1.10/31 dev enp4s0f0 proto kernel scope link src 10.105.1.11
10.105.1.12/31 dev enp4s0f1 proto kernel scope link src 10.105.1.13
bird> show route all
Table master4:
0.0.0.0/0 unicast [bgp_A 2024-11-17] * (100) [AS4212010101i]
via 10.105.1.10 on enp5s0f0
Type: BGP univ
BGP.origin: IGP
BGP.as_path: 4259105001 4212010101
BGP.next_hop: 10.105.1.10
BGP.local_pref: 0
unicast [bgp_B 2024-11-18] (100) [AS4212010101i]
via 10.105.1.12 on enp5s0f1
Type: BGP univ
BGP.origin: IGP
BGP.as_path: 4259205001 4212010101
BGP.next_hop: 10.105.1.12
BGP.local_pref: 0
38.145.72.193/32 unicast [direct1 2024-11-06] * (240)
dev em5
Type: device univ
# bird.conf
router id 172.18.xxx.yyy;
ipv4 table master4;
define LOCAL_NET = [ 38.145.72.193/32 ];
protocol direct {
ipv4;
interface em5,-*;
}
protocol kernel {
scan time 1;
merge paths yes limit 4;
ipv4 {
import none;
export filter {
if proto = direct1 then reject;
krt_prefsrc = 38.145.72.193;
accept;
};
};
}
protocol device {
scan time 1;
}
protocol bgp bgp_A {
description TOR A;
local 10.105.1.11 as 4290105101 ; # enp4s0f0
neighbor 10.105.1.10 as 4259105001; # TOR_A
path metric 1;
ipv4 {
import all;
export filter {
if net ~ LOCAL_NET then accept;
else reject;
};
next hop self;
};
}
protocol bgp bgp_B {
bfd;
description TOR B;
local 10.105.1.13 as 4290105101 ; # enp4s0f1
neighbor 10.105.1.12 as 4259205001; # TOR_B
default bgp_med 0;
default bgp_local_pref 0;
path metric 1;
ipv4 {
import all;
export filter {
if net ~ LOCAL_NET then accept;
else reject;
};
next hop self;
};
}
