Route Server Guide | LSIX - LayerSwitch Internet Exchange

About Route Servers

LSIX operates route servers to facilitate the exchange of BGP learned routes between members on the peering platform. One BGP session per address family to each route server is enough to exchange routes with every open peer on the fabric — a peering LAN that spans 15 data centres across 4 metros. Both IPv4 and IPv6 are served on the same dual-stack sessions.

The route servers run as a redundant pair: one in DFDC THG1 (The Hague) and one in Amsterdam. Peering with the route servers is optional — LSIX runs an open policy, and you are always free to set up bilateral sessions instead of, or alongside, the route servers. We recommend connecting to both for redundancy.

New ports are onboarded through a short quarantine VLAN before joining the production peering LAN; route server sessions are activated together with the port.

The LSIX Route Servers operate on servers running the BIRD routing daemon.

RFC7947 of the Internet Engineering Task Force (IETF) describes the specifications and properties for the implementation of a route server in more detail.

BGP Session Information

Hostname	IPv4	IPv6	ASN
rs1.lsix.net	`185.1.32.254`	`2001:7f8:8f::a504:9917:1`	49917
rs2.lsix.net	`185.1.32.253`	`2001:7f8:8f::a504:9917:2`	49917

BGP Recommended Settings

Max Prefixes IPv4	Max Prefixes IPv6	RIR MACRO IPv4	RIR MACRO IPv6
120,000	100,000	`AS-LSC-IXP-RS`	`AS-LSC-IXP-RS`

BGP Communities

The route servers honour both standard (RFC 1997) and large BGP communities for traffic engineering. The standard community actions are listed below; large-community equivalents follow the same action scheme.

Action	BGP Standard Community (RFC 1999)
Graceful Shutdown	`65535:0`
Blackhole	`65535:666`
no-export	`65535:65281`
no-advertise	`65535:65282`
Do not redistribute to $peeras	`0:$peeras`
Redistribute to $peeras	`49917:$peeras`
Do not redistribute	`0:49917`
Prepend once	`65001:0`
Prepend twice	`65002:0`
Prepend thrice	`65003:0`
Prepend once selective	`65001:$peeras`
Prepend twice selective	`65002:$peeras`
Prepend thrice selective	`65003:$peeras`

BGP Prefix Filtering

All routes received by the route servers are subject to RPKI origin validation — announcements with an invalid ROA state are rejected — and to IRR-based filtering built from each member's registered AS-SET. Every 24 hours the route servers regenerate the list of allowed prefixes per autonomous system number and apply it to the active filters.

Make sure your prefixes are covered by ROAs and that your AS-SET in the IRR is up to date before bringing up your sessions.

Example Configurations

The only required protocol on the exchange is BGP. Make sure you disable any other protocols on the port(s) facing the peering platform such as OSPF, ISIS, LLDP and STP.

# show interfaces xe-2/3/0
description LSIX;
unit 0 {
    family inet {
        address 185.1.32.XXX/24;
    }
    family inet6 {
        address 2001:7f8:8f::a50X:XXXX:1/64;
    }
}
# show protocols bgp group lsix
description IX:LSIX;
local-address 185.1.32.XXX;
import IMPORT-LSIX;
export EXPORT-LSIX;
family inet {
    any {
        prefix-limit {
            maximum 1000;
            teardown 90;
        }
    }
}
local-as 47869;
neighbor 185.1.32.XXX {
    description "Sample small peer";
    peer-as XXXXX;
}
neighbor 185.1.32.254 {
    description "LSIX RouteServer 1";
    family inet {
        any {
            prefix-limit {
                maximum 100000;
                teardown 90;
            }
        }
    }
    peer-as 49917;
}
# show policy-options policy-statement IMPORT-LSIX
term ATTRIBUTES-INET {
    from family inet;
    then {
        local-preference 400;
        community add IMPORT-FROM-PEERING;
    }
}
term ATTRIBUTES-INET6 {
    from family inet6;
    then {
        local-preference 400;
        community add IMPORT-FROM-PEERING;
    }
}
# show policy-options policy-statement EXPORT-LSIX
term SEND-ORIGINATES {
    from community SEND-ORIGINATES;
    then {
        origin igp;
        accept;
    }
}
term REJECT-REST {
    then reject;
}

# show interfaces
 ethernet eth0 {
     duplex auto
     hw-id 0c:c4:7a:59:23:02
     smp-affinity auto
     speed auto
     address 185.1.32.XXX/24
     address 2001:7f8:8f::a50X:XXXX:1/64
 }
 # show protocols bgp
 bgp XXXXX {
     neighbor 185.1.32.XXX {
         description "Sample small peer"
         peer-group lsix
         remote-as XXXXX
     }
     neighbor 185.1.32.254 {
         address-family {
             ipv4-unicast {
                 maximum-prefix 100000
             }
         }
         description "LSIX RouteServer #1"
         peer-group lsix
         remote-as 49917
     }
     peer-group lsix {
         address-family {
             ipv4-unicast {
                 maximum-prefix 10000
                 route-map {
                     export EXPORT-LSIX
                     import IMPORT-LSIX
                 }
             }
             ipv6-unicast {
                 maximum-prefix 50000
                 route-map {
                     export EXPORT-LSIX
                     import IMPORT-LSIX
                 }
             }
         }
     }
 }
 # show policy route-map IMPORT-LSIX
 rule 1 {
     action permit
     set {
         community XXXXX:12345
         local-preference 400
     }
 }
 # show policy route-map EXPORT-LSIX
 rule 1 {
     action permit
     match {
         community {
             community-list SEND-ORIGINATES
         }
     }
     set {
         origin igp
     }
 }
 rule 99 {
     action deny
 }

! Define a single-port VLAN for your LSIX port
vlan XX name "LSIX"
router-interface ve XX
untagged ethernet X/X

interface ethernet X/X
! Behave as a router
route-only
no spanning-tree
! Configure a port-name
port-name LSIX
! Configure your IP address
ip address 185.1.32.XXX/24
! Configure your IPv6 address
ipv6 address 2001:7f8:8f::a5XX:XXXX:1/64
! Don't do Router Advertisements
ipv6 nd suppress-ra
! No redirects
no ip redirect
no ipv6 redirect
! Configure router bgp
router bgp
 local-as XXXXX
 auto-shutdown-new-neighbors
 capability as4 enable
 neighbor lsix peer-group
 neighbor lsix-ip6 peer-group
 neighbor 185.1.32.XX1 remote-as 49917
 neighbor 185.1.32.XX1 peer-group lsix
 neighbor 185.1.32.XX1 maximum-prefix 100000
 neighbor 185.1.32.XX1 description "LSIX Route Server #1"
 neighbor 185.1.32.XX2 remote-as XXXXX
 neighbor 185.1.32.XX2 peer-group lsix
 neighbor 185.1.32.XX2 description "Sample big peer"
 neighbor 185.1.32.XX2 maximum-prefix 25000
 neighbor 185.1.32.XX3 remote-as XXXXX
 neighbor 185.1.32.XX3 peer-group lsix
 neighbor 185.1.32.XX3 description "Sample regular peer"
 neighbor lsix activate
 neighbor lsix route-map in IMPORT-LSIX
 neighbor lsix route-map out EXPORT-LSIX
 neighbor lsix-ip6 activate
 neighbor lsix-ip6 route-map in IMPORT-LSIX-IPV6
 neighbor lsix-ip6 route-map out EXPORT-LSIX
! Route-map sample
route-map IMPORT-LSIX permit 10
 match ip address prefix-list BOGONS
 set community  XXXXX:12345
 set metric none
 set local-preference 400
!
route-map IMPORT-LSIX-IPV6 permit 10
 match ipv6 address prefix-list BOGONS-INET6
 set community  XXXXX:12345
 set metric none
 set local-preference 400
!
route-map EXPORT-LSIX permit 60
 match community SEND-ORIGINATES
!

Route serverguide.