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Route Server

• About RS
• How to start using RS?
• RS routing policy
• BGP community attributes

About RS

The Route Server (RS) is a network service that simplifies peering between SPB-IX participants and allows them to reduce the number of individually administered peering sessions. The RS retransmits BGP announcements between the connected participants, thus peering with the RS means establishing peering relations with all the other SPB-IX participants connected to the RS.

Available on the common peering VLAN, the RS operates over IPv4 and IPv6 and supports 16bit and 32bit AS numbers. The RS hardware consists of 2 redundant servers located at Switching Station of Oktyabrskaya Railway and St.-Peterburg State University of Technology and Design.

How to start using RS?

To start using the RS, a participant must perform the following steps to establish a BGP peering session with AS43690 autonomous system:

1. Add peering with AS43690 to the routing policy description of your AS. The routing policy description must be maintained in RIPE, ARIN, or RADB Internet Routing Registry (IRR).

2. Send application from authorized contact address to spb-noc@ix.ru containing the ID of the organization, the AS number and the IP address of the border router (IPv4 and/or IPv6).

3. Configure BGP-sessions with both instances of the RS (see details below).

4. Disable first-as check in your BGP configuration by issuing no bgp enforce-first-as command.

* Configuration updates include checks and updates of information in the IRR, updates or the routing policy filters, application of changes to the configuration of the RS. The procedure takes from several minutes to one hour.

Information about SPB-IX participants peering with the RS may be retrieved from the RIPE database, see http://www.ripe.net/whois?searchtext=-T+aut-num+as43690, or whois -h whois.ripe.net as43690.

Use the RS Looking Glass to view and debug BGP announcements to the RS.

All participants using the RS must comply with the Technological Requirements.

RS routing policy

The RS exchanges the routing information with connected participants via BGP4 protocol as described in RFC4271. By default, the RS announces the best of all routes received from its peers. The Next-Hop attribute contains the IP-address of the host from RS received the announcement. The AS_PATH attribute is passed unchanged. Thus, the traffic is exchanged between RS peers directly.

The RS filters the incoming announcements according to the following principles:

• Announcement is not accepted if the last AS number in the AS_PATH attribute of the announced route does not match the origin field of the corresponding route and/or route6 object in IRR database.
• Announcement is not accepted if the route is not defined in the IRR routing policy description as announced to AS43690.
• Announcements of private networks, private ASs and the default route are not accepted.

BGP community attributes

Route Server supports two groups of BGP community attributes: basic and extra. Basic communities are applied in the table order.

Notes:

1. If BGP community attribute is not present or not-conformant with the list, a prefix is accepted and announced to all participants.

2. The looking glass displays prefixes announced to the RS and basic BGP communities. For extra BGP communities, only the result of their application is shown.

3. All announcements are set by default local-preference 100.

4. Prefixes with no-export attribute (65535:65281) are announced to participants with the attribute unchanged.

BGP communities for 32-bit AS numbers

To use BGP communities with 32-bit AS numbers, set peer-as values as listed in the following table: