protocols bgp <asn> peer-group <name> address-family ipv4-unicast allowas-in number <number>
Allows or disallows receiving BGP advertisements containing the AS path of the local router.
Readvertisement is disabled.
- asn
- The number for the AS in which this router resides. The number ranges from 1 through 4294967295.
- name
- The peer group name.
- number number
- The number of times to accept an AS path containing the readvertisement of the ASN of the local router. The numbers range from 1 through 10. The default is 3.
Configuration mode
protocols {
bgp asn {
peer-group name {
address-family {
ipv4-unicast {
allowas-in {
number number
}
}
}
}
}
}
Use the set form of this command to allow the router to accept BGP AS paths advertising the AS number of the router.
This situation could indicate a routing loop, and by default such an update is dropped. However, you can use this command to direct the router to accept updates readvertising its AS number for a specified number of times.
Use the delete form of this command to disallow readvertisement of the AS path of the router.
When you configure this command and do a soft reset in the peer, the BGP table should flush out the prefixes that have an as-path length that is more than the configured allowas-in value.
When soft-reconfiguration is enabled irrespective of the configured allowas-in value, all the received prefixes should be stored in Adj-Rib-In, and then allowas-in should be applied and prefixes with an as-path length more than the configured value should be flushed out of the BGP table. For more information on soft-reconfiguration, see protocols bgp <asn> neighbor <id> address-family ipv4-unicast soft-reconfiguration inbound.