Is it possible to set an IP address to an interface?

[Robért Guhr]

Hi,

is it possible to set an ipv4 address (e.g. "10.186.100.11/32" ) via bird
on a dummy interface called "anycast"?
I mean via the bird config not via bgp/ospf pushes.

Background:

I have setup four DNS server in two sites. All these DNS servers announces
10.186.100.11/32 (and 10.186.100.12/32) up to the routers to create an
anycast environment.
Currently 10.186.100.11/32 (and 10.186.100.12/32) are set fixed on the
dummy interface. Bird just imports these IP addresses.

We would like to use 10.186.100.11/32 and 10.186.100.12/32 as resolver in
/etc/resolv.conf
But if we stop the local DNS server then the dns resolution is no longer
possible because the addresses are hardcoded on the local interface and the
other three dns server will not be used.


Idee was to set the ip addreses via bird so that when we stop Bird and the
local DNS server, we automatically forward the DNS requests to the other
three servers.


I was hoping the direct protocol converts a route also to an ip address but
this seems not to be the case.
With the kernel protocol I can export the route to the kernel routing table
but that is not was I was want.

pns-b2-ns02 ~ # cat /etc/bird.conf
# Ansible managed

router id 10.186.244.12;

protocol device {
  scan time 10;
}

protocol direct {
  ipv4 {
    import none;
    export all;
  };
  interface "anycast";
}

protocol static {
  ipv4 {
    import all;
    export all;
  };
  route 10.186.100.11/32 via "anycast";
}

protocol kernel {
  ipv4 {
    import none;
    export all;
  };
}





pns-b2-ns02 ~ # birdc show route; echo; ip a show dev anycast; echo; ip r |
grep 10.186.100

BIRD 2.13.1 ready.
Table master4:
10.186.100.11/32     unicast [static1 17:22:18.282] * (200)
dev anycast

4: anycast: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state
UNKNOWN group default qlen 1000
    link/ether 8e:b5:2b:bf:0d:5e brd ff:ff:ff:ff:ff:ff
    inet 10.186.100.9/32 scope global noprefixroute anycast          #
<----- here should also be the address 10.186.100.11/32
       valid_lft forever preferred_lft forever

10.186.100.11 dev anycast proto bird scope link metric 32



Regards,
Robért
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