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Maybe I'm overthinking.. ?

Posted: Sat Jul 09, 2022 1:37 am
by joshhboss
I have a network im building and I have a management vlan just for the switches and another vlan just for the access points.
I was pinging in-between the switches.. No admittedly the Mikrotik to Mikrotik pings are perfect. 0ms. but when I ping these Cisco 3750x switches I get pings that are a little higher.. sometimes ranging from 2-40ms. Should I be concerned or no?

Re: Maybe I'm overthinking.. ?

Posted: Sat Jul 09, 2022 2:38 am
by anav
If you want lower pings on cisco you probably have to buy a yearly service for competitive pings.
Admittedly the cisco has to look at itself, which causes a very small delay.

Re: Maybe I'm overthinking.. ?

Posted: Sat Jul 09, 2022 2:52 am
by joshhboss
If you want lower pings on cisco you probably have to buy a yearly service for competitive pings.
Admittedly the cisco has to look at itself, which causes a very small delay.
has to look at itself ? I never knew that. so then this makes sense.. its nothing to be concerned about ? all my core switches now Mikrotik, I am using a pfsense box and edge routers for routing.. Ill start the battle for learning Mikrotik routing when I have the time. I am heading in that direction. the reason I keep the 3750s and the 2960s around is because of the tdr testing and ip device tracking.. those two features I dont think I could live without. And sadly the crs3XX series do not test cables even.

Re: Maybe I'm overthinking.. ?

Posted: Sat Jul 09, 2022 9:27 am
by jvanhambelgium
This is a LOCAL LAN in a single building?? I see 1% and 2% packet loss ? Something is a bit off here...
Reply times are, for a local LAN, quite high, unless that LAN & switches are extremely busy ?

Sure pinging a switch itself requires some CPU cycles from the control-plane to answer, while pinging "through" a switch stays on the data-plane/ASIC

Re: Maybe I'm overthinking.. ?

Posted: Sat Jul 09, 2022 6:47 pm
by chechito
sometimes cpu on a switch is small and does not reply ping consistently because it has another tasks with higher priority to do

try ping to another device on the same location to see if ping variation correlate

Re: Maybe I'm overthinking.. ?

Posted: Sat Jul 09, 2022 7:43 pm
by technick
I too have upgraded a cisco network to mikrotik, however I am not seeing any issues between switches/routers, between mikrotik and cisco. I would be concerned about the packet loss, priority queues or not you shouldn't be dropping any packets. Maybe you have a failing device somewhere in your infrastructure? the ping times seem laggy for sure. 40ms is pretty high for a single location ping.

How much bandwidth does this network carry at once?

Re: Maybe I'm overthinking.. ?

Posted: Mon Jul 11, 2022 8:30 am
by Buckeye
Josh,

If you want consistent pings, get yourself two dedicated Raspberry Pi boards. (I prefer Pi 4, but even a Pi 2 will be fine, but limited to a 100Mb connection.)

These are very useful for many things, iperf testing, capturing pcaps on a mirror port, using scapy to generate/capture packets, using vlans (with the vlan package loaded). You can even load up Kali for pen testing.

Even using hrping on a Windows 10 PC with 8GB RAM and HDD that has over committed memory (due to having too many Chrome Web pages open, for example) will get a lot of jitter reported, the point being that even the ping client can report jitter that doesn't really exist.

Also many switches have ping responses rate limited (which can lead to lost 'pings' that don't necessarily mean traffic is being dropped due to overutilization of a link, but just due to policy. And as others have mentioned, many switches treat these ping request as background tasks, so using a switch as a ping target isn't a good indication of actual network latency/jitter.

At least that's my experience.

Re: Maybe I'm overthinking.. ?

Posted: Fri Jul 15, 2022 12:46 pm
by mJohnso
Yes I am also getting confused

Re: Maybe I'm overthinking.. ?

Posted: Mon Jul 18, 2022 2:50 am
by joshhboss
Thank you everyone.. Ive noticed that the network has been working really well. The intense traffic is coming up in the next few days here but so far, im looking at ((4) CRS317-1G-16S+'s..(1) CRS328-24S-2QRM..(1) CRS328-24P-4S+, Big Netgate PFsense 32 gig router, with (2) Ubiquiti Edge routers, So far (22) 3750X Cisco Switch but I have 18 more that might go out, 199 Aps..(with 50 on the way for back ups)).. WISH me luck.. Ill update this forum as I get closer to the bulk of the clients connecting. On and I have a 10 gig internet connection with /27 publics and a 1 gig with 10 publics..

:)

Re: Maybe I'm overthinking.. ?

Posted: Sat Jul 23, 2022 11:48 am
by kevinds
I have a network im building and I have a management vlan just for the switches and another vlan just for the access points.
I was pinging in-between the switches.. No admittedly the Mikrotik to Mikrotik pings are perfect. 0ms. but when I ping these Cisco 3750x switches I get pings that are a little higher.. sometimes ranging from 2-40ms. Should I be concerned or no?
Only if there is an actual issue...