Compressed Routes Query

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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.

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Stephen Elliott

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Posted 3 years ago

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Grosjean, Stephane, Employee

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Can you share the result of the following command?

sh iproute reserved-entries statistics
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Stephen Elliott

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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 #

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Grosjean, Stephane, Employee

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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.
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Stephen Elliott

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excellent, thanks Stephane.  : )