Documentation for "get router info bgp paths"

[Fern-X]

Hello.

is there any official or helpful clues about "get router info bgp paths" printouts? I've assumed the numbers in parentheses are AS-Path count, but am failing to reconcile those numbers with "Total number of prefixes" from "get router info bgp regexp".

R's, Alex

[spoojary]

Check the doc : https://community.fortinet.com/t5/FortiGate/Technical-Tip-How-to-check-BGP-advertised-and-received-r...

[Fern-X]

Umm.. Did you read the question?

[AEK]

Hello

Seems not documented.

In my output there are no numbers in parentheses. Could you please post a sample output?

[Toshi_Esumi]

Mine is like below but those numbers don't add up to the total number of prefixes. No ASN ones are for re-distributed connected routes but 3 less than the (17). Then the rest seems to be doubled, like 15 for "65528" instead of (30).

fg40f-utm (root) # get router info bgp paths
Address Refcnt Path
[0x7fa385da80] (17)
[0x7fa385d980] (30) 65528
[0x7fa385d880] (832) 65528 xxxxx
[0x7fa385d4e0] (12) 65528 xxxxx 65512
[0x7fa385d9a0] (2) 65528 xxxxx 65516
[0x7fa385d760] (2) 65528 xxxxx 65517

.....

I would guess we wouldn't know what they're until open a ticket at TAC then push them to ask DEV side to get the answer.

Toshi

[AEK]

The documented output from Cisco cmd "show ip bgp paths" may help.

Router# show ip bgp paths

Address    Hash Refcount Metric Path
0x60E5742C    0        1      0 i
0x60E3D7AC    2        1      0 ?
0x60E5C6C0   11        3      0 10 ?
0x60E577B0   35        2     40 10 ?

Field Description

Address	Internal address where the path is stored.
Hash	Hash bucket where path is stored.
Refcount	Number of routes using that path.
Metric	The Multi Exit Discriminator (MED) metric for the path. (The name of this metric for BGP versions 2 and 3 is INTER_AS.)
Path	The autonomous system path for that route, followed by the origin code for that route.

From your output, I guess the number between parentheses is "Refcount", which represents the number of references to this path in the BGP routing table.

Ref:

https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/iproute_bgp/command/irg-cr-book/bgp-s1.html#wp1322...

[Toshi_Esumi]

Cisco's operation is even more confusing. Below is from one of our MPLS routers so need to specify the VRF name but the "paths" command should show in the same way. The routes using the path is only four in this VRF. But they're spread to three memory addresses and the total is 9. Probably it includes some historical information not only the current ones in the BGP table. FGT's set don't have multiple memory addresses for one set of AS path. Probably simply because the way it stores AS path info for BGP prefixes is different from Cisco's.

xxxrouter1#sh ip bgp vpnv4 vrf xxxx1 paths | i 65528 64515
0x144C84B4 771 5 0 65528 64515 ?
0x15254024 1976 2 0 65528 64515 ?
0x152543BC 3035 2 0 65528 64515 ?
xxxrouter1#sh ip bgp vpnv4 vrf xxxx1 | i 65528 64515
*>i 10.0.0.0/24 74.85.31.240 0 100 0 65528 64515 ?
*>i 10.0.1.0/24 74.85.31.240 0 100 0 65528 64515 ?
*>i 10.1.3.0/24 74.85.31.240 0 100 0 65528 64515 ?
*>i 192.168.3.0 74.85.31.240 0 100 0 65528 64515 ?

So the FortiOS's command is definitely trying to duplicate (or mimic) what Cisco IOS is showing (I have access to a Juniper router, which doesn't have an equivalent command). But what exactly the number represent would be unclear until somebody gets some explanation from DEV side.

Toshi

[Fern-X]

> Then the rest seems to be doubled, like 15 for "65528" instead of (30)

that’s the pattern I’m seeing, except for me there’s a different fraction because I’ve multiple VDOMs that are peeing with root VDOM in hub/spoke manner.

The usefulness of this command is that shown AS Paths span all VDOMs, so a shortcut to show all ASNs known  by device.

[Toshi_Esumi]

Acutally my original post was from FG40F with two VDOMs. But the second vdom doesn't have BGP setup. We have multi-VDOM units accommodating multiple customers. If it shows all of them, it would be less useful for us.

Toshi