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BGP error handling per RFC 7606 7.0.2

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BGP error handling per RFC 7606 7.0.2

BGP error handling on malformed attributes in BGP UPDATE messages is extended to additional techniques referenced in RFC 7606 (see RFC 7606 for details). The FortiGate uses one of the three approaches to handle malformed attribute, in order of decreasing severity:

  1. Notification and Session reset

  2. Treat-as-withdraw

  3. Attribute discard

When a BGP UPDATE message contains multiple malformed attributes, the most severe approach that is triggered by one of the attributes is followed.

The following table lists the BGP attributes, and how FortiGate handles a malformed attribute in the UPDATE message:

BGP attribute

Handling

origin Handled by the treat-as-withdraw approach.
AS path Handled by the treat-as-withdraw approach.
AS 4 path Handled by the attribute discard approach.
aggregator Handled by the attribute discard approach.
aggregator 4 Handled by the attribute discard approach.
next-hop Handled by the treat-as-withdraw approach.
multiple exit discriminator Handled by the treat-as-withdraw approach.
local preference Handled by the treat-as-withdraw approach.
atomic aggregate Handled by the attribute discard approach.
community Handled by the treat-as-withdraw approach.
extended community Handled by the treat-as-withdraw approach.
originator Handled by the treat-as-withdraw approach.
cluster Handled by the treat-as-withdraw approach.
PMSI Handled by the treat-as-withdraw approach.
MP reach Handled by the notification message approach.
MP unreach Handled by the notification message approach.
attribute set Handled by the treat-as-withdraw approach.
AIGP Handled by the treat-as-withdraw approach.
Unknown If the BGP flag does not indicate that this is an optional attribute, this malformed attribute is handled by the notification message approach.

BGP error handling per RFC 7606 7.0.2

BGP error handling on malformed attributes in BGP UPDATE messages is extended to additional techniques referenced in RFC 7606 (see RFC 7606 for details). The FortiGate uses one of the three approaches to handle malformed attribute, in order of decreasing severity:

  1. Notification and Session reset

  2. Treat-as-withdraw

  3. Attribute discard

When a BGP UPDATE message contains multiple malformed attributes, the most severe approach that is triggered by one of the attributes is followed.

The following table lists the BGP attributes, and how FortiGate handles a malformed attribute in the UPDATE message:

BGP attribute

Handling

origin Handled by the treat-as-withdraw approach.
AS path Handled by the treat-as-withdraw approach.
AS 4 path Handled by the attribute discard approach.
aggregator Handled by the attribute discard approach.
aggregator 4 Handled by the attribute discard approach.
next-hop Handled by the treat-as-withdraw approach.
multiple exit discriminator Handled by the treat-as-withdraw approach.
local preference Handled by the treat-as-withdraw approach.
atomic aggregate Handled by the attribute discard approach.
community Handled by the treat-as-withdraw approach.
extended community Handled by the treat-as-withdraw approach.
originator Handled by the treat-as-withdraw approach.
cluster Handled by the treat-as-withdraw approach.
PMSI Handled by the treat-as-withdraw approach.
MP reach Handled by the notification message approach.
MP unreach Handled by the notification message approach.
attribute set Handled by the treat-as-withdraw approach.
AIGP Handled by the treat-as-withdraw approach.
Unknown If the BGP flag does not indicate that this is an optional attribute, this malformed attribute is handled by the notification message approach.