
OPERATIONAL DEFECT DATABASE
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In a segment-routing mpls setup using non-default SRGB range, after a router reload, ISIS may fail to allocate the SRGB range: RP/0/RSP0/CPU0:Jan 19 22:52:42.549 IST: isis[1013]: %ROUTING-ISIS-4-SRGB_ALLOC_FAIL : ISIS (core): SRGB allocation failed: 'SRGB reservation not successful for [16000,275999], SRGB (16000 275999, SRGB_ALLOC_CONFIG_PENDING, 0x3) (So far 32 attempts). Make sure label range is free' And all services depending on SR and SRGB will fail. Issue is very timing sensitive and very difficult to hit.
- can only be hit after a router reload - segment-routing mpls setup using non-default SRGB range only: router isis address-family [ipv4 | ipv6] unicast segment-routing mpls segment-routing global-block Default SRGB range is: 16000 23999
There's no workaround. Because it’s very difficult to hit, a 2nd reload will recover the router most of the time.
Since router reload is always disruptive and router will almost always recover after a 2nd reload, the impact is not as big as it seems.
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