BGP - Prefix Count

RouterOS RouterOS beta
1

Hi all

I stumbled across something that looks like a bug to me.
When prefixes get removed from an already running session, “Prefix Count” shows a value of around 4,294,967,295 (32-bit unsigned integer?) and stays in this area until the session gets restarted.
As you can see in the image below, the number of prefixes in the routing table looks plausible though.
prefix.png
In this scenario, the first two sessions should show a prefix count of maybe 0 - 10.

Is this a known bug?

Edit:
After the two sessions got restartet it looks like this:
prefix2.png
ROS Version: 7.11beta2

  • Mat
2

Hello Mat
I have exactly the same problem with version 7.11.2
I’m a bit disappointed that Mikrotik hasn’t replied to you since June 2023, It’s inconceivable to me…
Regards.
Capture d’écran 2023-10-10 à 00.08.10.png

3

Hi Angoran

yes it’s a bit disappointing that I didn’t get a reply. I mean a simple “yes it’s a known bug, we’re working on it”, would have been better than what I’ve got.
Sure it seems to be a minor bug, but on the other hand it’s quite annoying to administer a system that shows such impossible values.

  • Mat
4

Same story here.

Also find it amusing that you still have to revert to looking at packet dumps, to see what is actually advertised too.

ROSv7 feels like a pet project that got started and just never got finished. Def. not prod ready IMHO.

5

Well, this forum is mainly for inter-user communication. When you want a reply from support and/or some chance your topic gets put on an action list, it is better to create a ticket in the support portal: https://help.mikrotik.com/servicedesk/servicedesk/

6

Good evening pe1chl,
I wrote to support and they had the same attitude, no reply, no consideration.
All the best.

7

overall on v7 BGP development/improvement is a bit stalled at MT

8

This problem should be already fixed in v7.12

9

Maybe you can use this script to show you prefix counts on commandline:

/system script
add comment="print BGP prefix count" dont-require-permissions=no name=\
    bgp-prefixes owner=admin policy=read source="/routing/bgp/session {\r\
    \n   :global prefixes ({});\r\
    \n   :global active ({});\r\
    \n   :local maxlen 0;\r\
    \n   :foreach ses in=[find] do={\r\
    \n      :set \$remote [get \$ses \"remote.address\"]\r\
    \n      :set \$name [get \$ses name]\r\
    \n      :if ([:len \$name] > \$maxlen) do={\r\
    \n         :set \$maxlen [:len \$name]\r\
    \n      }\r\
    \n      :set (\$prefixes->\$name) [/routing/route/print count-only  where \
    !filtered and belongs-to=\"bgp-IP-\$remote\"]\r\
    \n      :set (\$active->\$name) [/routing/route/print count-only  where ac\
    tive and belongs-to=\"bgp-IP-\$remote\"]\r\
    \n   }\r\
    \n   :set \$name \"Session                         \"\r\
    \n   :set \$name [:pick \$name 0 \$maxlen]\r\
    \n   :put \"\"\r\
    \n   :put \"\$name : Prefixes Active\"\r\
    \n   :put \"----------------------------------\"\r\
    \n   :foreach name,prefix in=\$prefixes do={\r\
    \n      :set \$act (\$active->\$name)\r\
    \n      :set \$name (\$name.\"                              \")\r\
    \n      :set \$name [:pick \$name 0 \$maxlen]\r\
    \n      :set \$prefix (\$prefix.\"          \")\r\
    \n      :set \$prefix [:pick \$prefix 0 8]\r\
    \n      :put \"\$name : \$prefix \$act\"\r\
    \n   }\r\
    \n}\r\
    \n"

Use /system/script/run bgp-prefixes to show the current number of prefixes for each peer, both received and active.
It first prints a couple of lines with only numbers, ignore that (it is due to the strange design of scripting language).
After that it prints a header and a line for each peer.

10

Hello pe1chl,
I tested your script and it works.
Thanks a lot!