On 30 January 2017 at 08:45, Marcin Kurek <[email protected]> wrote: > Hi all, > > I came across the following label allocation limit on ASR920 > (ASR-920-24SZ-IM) platform: > > ASR920#show platform hardware pp active sdm current > CYLON_NUM_MPLS_INGRESS_LABELS = 38912 > CYLON_NUM_MPLS_EGRESS_LABELS = 28500 > > I understand that egress labels are locally generated labels advertised to > peers. Ingress labels are received from remote peers. What I don't > understand is how to interpret this ingress limit. > > If there is a limit on labels received from peers, does it affect VPN labels > too? For example, if I receive 10 000 prefixes from remote PE (per-prefix > label allocation), does it mean that I've just used 10 000 out of 38912 > limit?
I would also like some clarity on this but yes I believe that is how it works. If you are using per-prefix labelling and receive 10k labelled routing advertisements that is 10k of your egress label space gone. The ME3600X/ME3800X actually have one shared MPLS space in TCAM. The ME3600X for example is listed as having a 22,000 label limit by default and the output from "show mpls label range" shows the usable label range as 16 to 21999 (so just under 22k). If you look at the TCAM with "show platform aspdma template | i MPLS" you can see they can hold a total of 28.6k MPLS labels however only 22K of them can be used for local labels (ingress labels) but up to 28.5k can be used for egress labels. ME3600X: #sh platform aspdma template | i MPLS … NILE_NUM_MPLS_INGRESS_LABELS = 22000 NILE_NUM_MPLS_EGRESS_LABELS = 28500 … EMPLS3LD_TABLE = 28672 So of the maximum 28.6k labels it can store no more than 22k of them can be ingress labels and no more than 28.5k can be egress labels. I have some more notes here if you’re board: https://null.53bits.co.uk/index.php?page=inter-as-mpsl-optionb-mpls-label-usage Since the ASR920 uses the Cylon ASIC which is like a “NILE version 2” perhaps they also have the same behaviour? The stats Cisco gave us were: MPLS Ingress Labels 16,000 MPLS Egress Labels 28,000 ASR920#show mpls label range Downstream Generic label region: Min/Max label: 16/32767 ^ That says to me that 32k ingress / local labels can be assigned? ASR920#show platform hardware pp active sdm current | i MPLS CYLON_NUM_MPLS_INGRESS_LABELS = 38912 CYLON_NUM_MPLS_EGRESS_LABELS = 28500 ^ This however says to me that 38.9k can be assigned? It’s not clear how many labels have been assigned either: "show platform hardware pp active tcam usage" isn't showing MPLS usage. "show platform hardware pp active tcam utilization ?" isn't showing MPLS usage. ASR920#show platform hardware pp active resource-usage summary 0 | i Type|MPLS Type Maximum Allocated Freed In Use Available for use EMPLS3LD ... 26624 100350 98663 1687 24937 EMPLSINTD ... 8192 2660 2549 111 8081 EMPLS3LD, is that saying a max of 26k labels? Perhaps one for Warris et al. Cheers, James. _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
