topic RE: Compressed Routes Query in ExtremeSwitching (EXOS/Switch Engine)

Compressed Routes Query

Stephen_Elliot1 — Fri, 08 Jan 2016 17:35:00 GMT

Hi all, Happy New Year!
I'm seeking a bit of clarification on the show iproute command output.
I have an x450-e which was getting close to the hardware limit of 464 routes so I've turned on route compression.
I have a default route learned via OSPF from the same gateway as most of my other routes so my iproute summary now looks like this....

Slot-1 NET-ESXSTACK.6 # sh ipr sum
=================ROUTE SUMMARY=================
Mask distribution:
1 default routes 19 routes at length 21
18 routes at length 23 189 routes at length 24
34 routes at length 25 23 routes at length 26
50 routes at length 27 2 routes at length 28
1 routes at length 29 30 routes at length 30
31 routes at length 32

Route origin distribution:
176 OSPFExt1 210 OSPFIntra 12 Direct

Total number of routes = 398
Total number of compressed routes = 383

Slot-1 NET-ESXSTACK.7 #

Could anyone confirm that this actually means I've now only got 15 hardware routes and hence, loads of spare hardware route capacity?

Many thanks.

RE: Compressed Routes Query

Stephane_Grosj1 — Fri, 08 Jan 2016 17:52:00 GMT

Can you share the result of the following command?

sh iproute reserved-entries statistics

RE: Compressed Routes Query

Stephen_Elliot1 — Fri, 08 Jan 2016 18:05:00 GMT

Thanks Stephane, that's confirmed it - 15 routes + 48 local routes in the HW table. There are also a number of routes in the HW L3 Hast Table, but the total of all these is well below the 480 maximum.

Slot-1 NET-ESXSTACK-29-GPSPcr.1 # sh ipr reserved-entries stat
|-----In HW Route Table----| |--In HW L3 Hash Table--|
# Used Routes # IPv4 Hosts IPv4 IPv4 IPv6 IPv4
Slot Type IPv4 IPv6 Local Remote Local Rem. Loc. MCast
---- ---------------- ------ ------ ------ ------ ----- ----- ---- -----
1 X450e-24p 15 0 48 0 91 0 0 11
2 X450e-24p 15 0 48 0 91 0 0 11
3 - - - - - - - -
4 - - - - - - - -
5 - - - - - - - -
6 - - - - - - - -
7 - - - - - - - -
8 - - - - - - - -

Theoretical maximum for each resource type:
X440 32 16 64 64 509 512 256 * 256
"e"-series 480 240 512 512 2045 2048 1024 * 2048
"a"-series 12256 6128 8189 12288 8189 8192 4096 * 5000
X650, E4G-200 12256 6128 8189 12288 8189 8192 4096 * 6000
X460, E4G-400 12256 6128 12288 12288 16381 16384 8192 * 6000
X670-48x, X670V-48x 16352 8176 8189 16384 8189 8192 4096 * 4096
X670V-48t 16352 8176 16381 16384 16381 16384 8192 * 6000
X480(40G4X) 16352 8176 8189 16384 8189 8192 4096 * 4096
X480 262112 8192 16381 40960 16381 16384 8192 * 6000

Flags: (!) Indicates all reserved route entries in use.
(d) Indicates only direct IPv4 routes are installed.
(>) Some IPv6 routes with mask > 64 bits are installed and do not use
entries in the internal HW Route Table.
(R) IPv6 hosts in external HW Route Table.
(*) Assumes IP Multicast compression is on.
(M) IPMC entries stored in L2 MAC Table when lookup-key is 'mac-vlan'.
Slot-1 NET-ESXSTACK-29-GPSPcr.2 #

RE: Compressed Routes Query

Stephane_Grosj1 — Fri, 08 Jan 2016 18:19:00 GMT

To understand the output further.

- show iproute {summary} gives a view into the RIB (software, in memory, learn by all protocols)
- show iproute reserved-entries stat gives a view to the FIB (the hardware, all the best routes for LPM)

That command (sh ipr reserved-entries stat) gives you information on HW usage of LPM, Hosts and Multicast resources, both for IPv4 and IPv6.

So you have 15 LPM routes in HW.
As for the Hosts (ARP) you have 91 + 48 = 139 entries in HW. The distribution of the Hosts (LPM + L3 Hash tables) is due to some clever EXOS optimization that would be too long to explain here.
And you also have 11 Multicast entries.

RE: Compressed Routes Query

Stephen_Elliot1 — Fri, 08 Jan 2016 18:36:00 GMT

excellent, thanks Stephane. : )