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:
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Notification and Session reset
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Treat-as-withdraw
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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. |