LINX maintains route servers at each of the Peering LANs allowing members to establish multilateral peering with other participants.

Connect to the Route Servers

The Route Servers use the BIRD distribution with the Ubuntu Server Linux distribution.

Technical Details are as follows:

• AS Number:8714

Server	Type	LAN	IPv4 Address	IPv6 Address
rs1.lon1	BIRD	LINX LON1	195.66.225.230	2001:7f8:4::220a:1
rs3.lon1	BIRD	LINX LON1	195.66.225.231	2001:7f8:4::220a:2
rs2.lon2	BIRD	LINX LON2	195.66.237.231	2001:7f8:4:1::220a:1
rs4.lon2	BIRD	LINX LON2	195.66.237.230	2001:7f8:4:1::220a:2
rs1.man1	BIRD	LINX Manchester	195.66.244.230	2001:7f8:4:2::220a:1
rs2.man1	BIRD	LINX Manchester	195.66.244.231	2001:7f8:4:2::220a:2
rs1.car1	BIRD	LINX Wales	195.66.228.230	2001:7f8:4:4::220a:1
rs1.sco1	BIRD	LINX Scotland	195.66.246.230	2001:7f8:4:3::220a:1
rs1.nva1	BIRD	LINX NoVA	206.55.196.230	2001:504:31::220a:1
rs2.nva1	BIRD	LINX NoVA	206.55.196.231	2001:504:31::220a:2

Policy control is done by use of BGP Standard Communities and BGP Extended Communities. Members may tag their routes with the following to control policy via the route server.

The model is as follows:

block announcement of a route to a certain peer	0:peer-as	rt:0:peer-as
announcement of a route to a certain peer	8714:peer-as	rt:8714:peer-as
block announcement of a route to all peers	0:8714	rt:0:8714
announcement of a route to all peers	8714:8714	rt:8714:8714

If none of the above communities is present then the default behaviour is to advertise the prefix to all peers.

LINX is validating prefixes at ingress on all route servers. The validation is based on RPKI and IRR Object presence.

For RPKI validation we build a ROA table from IRR trust anchors and for IRR Object presence we build a list of valid origin ASN and prefixes based on route objects. Refines/more specifics of valid route objects are rejected.

We are looking for a valid AS-SET in the members PeeringDB record. If no valid AS-SET is found, we use the members ASN only, unless the member has provided us other information.

The results of the validation is reflected in communities which are being added at ingress:

• 8714:65011 = Prefix is present in an AS's announced AS/AS-SET
• 8714:65021 = Prefix is not present in an AS's announced AS/AS-SET
• 8714:65010 = Prefix has valid Origin AS in AS-SET
• 8714:65020 = Prefix has no valid Origin AS in AS-SET
• 8714:65012 = Prefix is RPKI VALID
• 8714:65022 = Prefix is RPKI INVALID
• 8714:65023 = Prefix is RPKI UNKNOWN

The prefix validation will always occur, and members can check the communities being set to their prefixes, and as such see the result of the validation checks through the route server looking glass interface.

Prefixes will only be accepted on the following criteria where,

1. Prefixes tagged with communities 8714:65010 (valid Origin AS in AS-SET) & 8714:65012 (RPKI VALID) or
2. Prefixes tagged with communities 8714:65010 (valid Origin AS in AS-SET) & 8714:65011 (Prefix is present in an AS's announced AS/AS-SET) & 8714:65023 (RPKI UNKNOWN) .

All other prefixes will be filtered at egress.

Any member who prefers to receive an unfiltered set of prefixes can request to opt-out of the filtering by contact our NOC at support@linx.net.

Looking Glass for route-servers is now accessible.

Corrupt AS path & Malformed AS-Path issues

Some members who use Cisco, Brocade and Huawei devices to peer with may encounter issues in establishing peering sessions and may see notifications of invalid or corrupt AS path and Malformed AS-path in their device logs. Something similar to:

Sep 1 08:40:40.498 UTC: %BGP-5-ADJCHANGE: neighbor 195.66.225.230 Up
Sep 1 08:40:41.506 UTC: %BGP-5-ADJCHANGE: neighbor 195.66.225.230 Down BGP Notification sent
Sep 1 08:40:41.506 UTC: %BGP-3-NOTIFICATION: sent to neighbor 195.66.225.230 3/11 (invalid corrupt AS path) 11 bytes 40020802 033C3424 580097

This issue is caused where the peering device does not like to receive updates from the route-server where the first AS in the path is not the route-server AS.

To work around this please use one of the vendor specific commands in your router configuration.

Cisco/Quagga/Brocade/Arista

router bgp <ASN>
no bgp enforce-first-as

Huawei

bgp <ASN>
undo check-first-as

If members are having trouble peering with the route servers please contact support.

For more information on Route Server statistics, please look at stats.linx.net/rs.

NB: This page only lists established sessions