The Juniper router configured for MSDP must limit the amount of source-active messages it accepts on per-peer basis.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-253981 | JUEX-RT-000090 | SV-253981r843976_rule | CCI-001368 | low |
| Description | ||||
| To reduce any risk of a denial-of-service (DoS) attack from a rogue or misconfigured MSDP router, the router must be configured to limit the number of source-active messages it accepts from each peer. | ||||
| STIG | Date | |||
| Juniper EX Series Switches Router Security Technical Implementation Guide | 2024-06-10 | |||
Details
Check Text (C-253981r843976_chk)
Review the router configuration to determine if it is configured to limit the amount of source-active messages it accepts on a per-peer basis.
[edit protocols]
msdp {
active-source-limit {
maximum <1..1000000>;
threshold <1..1000000>;
log-warning <percent to log warning>;
}
local-address <lo0 address>;
<additional configuration>
peer <address> {
active-source-limit {
maximum <1..1000000>;
threshold <1..1000000>;
log-warning <percent to log warning>;
}
authentication-key "hashed PSK"; ## SECRET-DATA
}
}
Note: Both the global, and the peer limit, are applied to every MSDP peer, and Junos applies the most restrictive limit. The maximum value sets the upper limit for source-active messages and the threshold value determines when Junos begins Random Early Detection (RED) dropping to alleviate congestion. The log-warning value is a percent where Junos begins generating syslog messages.
If the router is not configured to limit the source-active messages it accepts, this is a finding.
Fix Text (F-57384r843975_fix)
Configure the MSDP router to limit the amount of source-active messages it accepts from each peer.
set protocols msdp active-source-limit maximum <1..1000000>
set protocols msdp active-source-limit threshold <1..1000000>
set protocols msdp active-source-limit log-warning <percent to log warning>
<additional configuration>
set protocols msdp peer <address> active-source-limit maximum <1..1000000>
set protocols msdp peer <address> active-source-limit threshold <1..1000000>
set protocols msdp peer <address> active-source-limit log-warning <percent to log warning>