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StubArea51
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[bug] Issue with unexpected advertisement of OPSFv3 prefix

Wed Sep 30, 2020 4:45 pm

I'm doing some lab work with IPv6 routing and ROS7.1beta2 CHR. I'm trying to understand why OSPFv3 is advertising a specific prefix as I didn't explicitly configure it to be advertised and it doesn't show up as an external route indicating redistribution.

Here is the network topology

Image


The prefix shows up in BGP as I had intended but it's being replaced by OSPFv3 as the active route

[admin@CORE-1] > ipv6/route/print where dst-address=2001:db8:101::11
Flags: D - DYNAMIC; A - ACTIVE; b - BGP, o - OSPF, m - MODEM; + - ECMP
Columns: DST-ADDRESS, GATEWAY, DISTANCE
        DST-ADDRESS       GATEWAY                      DIS
  DAo+  2001:db8:101::11  fe80::5201:ff:fe01:0%ether1  110
  D b   2001:db8:101::11  2001:db8:127::12             200
  DAo+  2001:db8:101::11  fe80::5201:ff:fe01:1%ether3  110
  D b+  2001:db8:101::11  2001:db8:127::11             200

The LSAs received on CORE-1 indicate that it's a Router LSA (0x2001) which to me means that it should be explicitly advertised via configuration.

 4  D instance=IPv6 area=area-0 type="intra-area-prefix"
      originator=100.127.0.11 id=0.0.0.1 sequence=0x80000094 age=73
      checksum=0x729E body=
        ref-type=router
        ref-id=0.0.0.0
        ref-router-id=100.127.0.11
            prefix=2001:db8:126:1::/126
            prefix=2001:db8:127::11
            prefix=2001:db8:101::11
            prefix=2001:db8:126:3::/126

My expectation is the prefix should only be advertised if it's listed under the interface section - which it is not. Is that correct or am I missing something?

/routing ospf interface
add area=area-0 network=2001:db8:126:1::/126 network-type=point-to-point
add area=area-0 network=2001:db8:127::11/128
add area=area-0 network=2001:db8:126:3::/126 network-type=point-to-point

Config of PE-1
/interface bridge
add name=lo0
add name=lo1
/interface wireless security-profiles
set [ find default=yes ] supplicant-identity=MikroTik
/ip vrf
add list=all name=main
/routing bgp template
add address-families=ip,ipv6 as=8675309 instance=default name=ASN-8675309
/routing ospf instance
add name=IPv6 router-id=100.127.0.11 version=3
/routing ospf area
add area-id=0.0.0.0 instance=IPv6 name=area-0
/ip address
add address=100.127.0.11 interface=lo0 network=100.127.0.11
/ip dhcp-client
add disabled=no interface=ether1
/ipv6 address
add address=2001:db8:126:1::2/126 advertise=no interface=ether1
add address=2001:db8:127::11/128 advertise=no interface=lo0
add address=2001:db8:101::11/128 advertise=no interface=lo1
add address=2001:db8:126:3::2/126 advertise=no interface=ether2
/routing bgp connection
add local.address=2001:db8:127::11 .role=ibgp-rr-client remote.address=\
    2001:db8:127::1 .as=8675309 template=ASN-8675309
/routing ospf interface
add area=area-0 network=2001:db8:126:1::/126 network-type=point-to-point
add area=area-0 network=2001:db8:127::11/128
add area=area-0 network=2001:db8:126:3::/126 network-type=point-to-point
/system identity
set name=PE-1

Config of PE-2
/interface bridge
add name=lo0
/interface wireless security-profiles
set [ find default=yes ] supplicant-identity=MikroTik
/ip vrf
add list=all name=main
/routing bgp template
add address-families=ip,ipv6 as=8675309 instance=default name=ASN-8675309
/routing ospf instance
add name=IPv6 router-id=100.127.0.12 version=3
/routing ospf area
add area-id=0.0.0.0 instance=IPv6 name=area-0
/ip address
add address=100.127.0.12 interface=lo0 network=100.127.0.12
/ip dhcp-client
add disabled=no interface=ether1
/ipv6 address
add address=2001:db8:126:2::2/126 advertise=no interface=ether1
add address=2001:db8:127::12/128 advertise=no interface=lo0
/routing bgp connection
add local.address=2001:db8:127::12 .role=ibgp-rr-client remote.address=\
    2001:db8:127::1 .as=8675309 template=ASN-8675309
/routing ospf interface
add area=area-0 network=2001:db8:126:2::/126 network-type=point-to-point
add area=area-0 network=2001:db8:127::12/128
/system identity
set name=PE-2

Config of CORE-1
/interface bridge
add name=lo0
/interface wireless security-profiles
set [ find default=yes ] supplicant-identity=MikroTik
/ip vrf
add list=all name=main
/routing bgp template
add address-families=ip,ipv6 as=8675309 instance=default name=ASN-8675309
/routing ospf instance
add name=IPv6 router-id=100.127.0.1 version=3
/routing ospf area
add area-id=0.0.0.0 instance=IPv6 name=area-0
/ip address
add address=100.127.0.1 interface=lo0 network=100.127.0.1
/ip dhcp-client
add disabled=no interface=ether1
/ipv6 address
add address=2001:db8:126:1::1/126 advertise=no interface=ether1
add address=2001:db8:127::1/128 advertise=no interface=lo0
add address=2001:db8:126:2::1/126 advertise=no interface=ether2
add address=2001:db8:126:3::1/126 advertise=no interface=ether3
/routing bgp connection
add listen=yes local.address=2001:db8:127::1 .role=ibgp-rr remote.address=\
    2001:db8:127::11 template=ASN-8675309
add listen=yes local.address=2001:db8:127::1 .role=ibgp-rr remote.address=\
    2001:db8:127::12 template=ASN-8675309
/routing ospf interface
add area=area-0 network=2001:db8:126:1::/126 network-type=point-to-point
add area=area-0 network=2001:db8:127::1/128
add area=area-0 network=2001:db8:126:2::/126 network-type=point-to-point
add area=area-0 network=2001:db8:126:3::/126 network-type=point-to-point
/system identity
set name=CORE-1
Last edited by StubArea51 on Mon Oct 05, 2020 2:21 pm, edited 1 time in total.
 
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StubArea51
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Re: Issue with unexpected advertisement of OPSFv3 prefix

Mon Oct 05, 2020 2:21 pm

I tried with a simpler config and got the same result. This appears to be a bug and not configuration related.
 
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StubArea51
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Re: [bug] Issue with unexpected advertisement of OPSFv3 prefix  [SOLVED]

Fri Oct 09, 2020 3:26 pm

I may have found an answer to this in the v7 docs. I am going to test this with an empty route filter and see if it only advertises interfaces in OSPF that are configured.

EDIT: 10/10/2020 - This was the issue - verified it in the original lab

https://help.mikrotik.com/docs/display/ ... g+Examples

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