Packet loss on SG220-26P

[itsthealphanoob]

Hello, I have a SG220-26P i picked up from marketplace. I have very little experience with managed switches and even less with cisco switches. Im having an issue with packet loss.

basically any device that is not connected to the switch can ping the switch itself with no packet loss, if you ping a device that is connected to the switch there is 50%-100% packet loss

the switch itself can ping any device on the network either connected to the switch or not connected to the switch, the switch can also ping outside the network with no problem

any device that is connected to the switch can ping the switch or any other device that is also connected to the switch successfully, if any device connected to the switch pings a device that is not connected to the switch or is not on the network there's is 50%-100% packet loss

I have been stumped on this for a few days now and cant seem to figure it out, I hope that explanation makes some kind of sense and that someone knows how to solve this issue.

[Flavio Miranda]

@itsthealphanoob 

"any device that is connected to the switch can ping the switch or any other device that is also connected to the switch successfully,"

"if any device connected to the switch pings a device that is not connected to the switch or is not on the network there's is 50%-100% packet loss"

 If you run a trace route from a device connected to the switch to a device not connected to the switch, how is look like? Can you share this information?

One device that is not connected to the switch probably is connected to another device and there will be a path between this device and this switch. Maybe more than one path. This could be the problem.

Based on the first statement, I dont see why the problem is on the switch if the device can ping the switch and other devices on the switch.

[itsthealphanoob]

i did a trace route from a device connected to the switch to one that is not, I have attached an image, the weird part about this is pings and trace routes both tell me the device is unreachable but I can connect to services on the devices from within the network and outside the network.

[Flavio Miranda]

You probably have something blocking ICMP, it could be an Access list on the switch or some firewall somewhere.

[itsthealphanoob]

would you know where to check for those, I believe I ruled out firewall issues already but I could be wrong. Im flying a little blind here

[Flavio Miranda]

Well, If you share the switch config I can tell you If there some access list on It.

 Now, about firewall, It would be more difficult as this is another device probably.

[itsthealphanoob]

as far as fire wall i will look into that now, here is my config

config-file-header
SwitchDED59F
v1.1.3.1
CLI v1.0
@
!
!
jumbo-frame 10000
management vlan ip-address 192.168.2.222 mask 255.255.255.0
no management vlan ip dhcp client
ip default-gateway 192.168.2.1
no ip domain lookup

!
!
!
voice vlan oui-table add 00:E0:BB 3COM
voice vlan oui-table add 00:03:6B Cisco
voice vlan oui-table add 00:E0:75 Veritel
voice vlan oui-table add 00:D0:1E Pingtel
voice vlan oui-table add 00:01:E3 Siemens
voice vlan oui-table add 00:60:B9 NEC/Philips
voice vlan oui-table add 00:0F:E2 H3C
voice vlan oui-table add 00:09:6E Avaya
!
!
!
!
spanning-tree mode mstp
spanning-tree mst configuration
name "2C:AB:EB:DE:D5:9F"
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
interface po1
switchport mode trunk uplink
!
interface gi1
power inline never
!
interface gi2
power inline never
!
interface gi3
power inline never
!
interface gi4
power inline never
!
interface gi5
power inline never
!
interface gi6
power inline never
!
interface gi7
power inline never
!
interface gi8
power inline never
!
interface gi9
power inline never
!
interface gi10
power inline never
!
interface gi11
power inline never
!
interface gi12
power inline never
!
interface gi13
power inline never
!
interface gi14
power inline never
!
interface gi15
power inline never
!
interface gi16
power inline never
!
interface gi17
power inline never
!
interface gi18
power inline never
!
interface gi19
power inline never
!
interface gi20
power inline never
!
interface gi21
power inline never
!
interface gi22
power inline never
!
interface gi23
power inline never
!
interface gi24
power inline never
!
interface gi25
switchport mode trunk uplink
!
interface gi26
switchport mode trunk uplink
speed auto 1000
duplex full
!
!
!

[Flavio Miranda]

Switch is not blockimg anything. Make sure you dont have firewall enable on PCs or some device.

[itsthealphanoob]

so i have determined that the cause of the issue is the link between the switch and router, I have changed cables and ports and have also played with some setting in the router and cant seem to find the issue, is it possible there's a setting in the switch that should be tweaked

[Flavio Miranda · Accepted solution]

Your switch's config is extremally simple. I dont believe the switch is causing It due configuration. Unless this is a bug and you can try to upgrade to make sure.

[marce1000 · Accepted solution]

 - Make sure to use the latest firmware on the device : https://software.cisco.com/download/home/284973404/type/284971397/release/1.2.1.5
   If problems persist , check the logs on it to get further insights ,

 M.

[itsthealphanoob]

Thank you, everyone, for your help, I have learned quite a bit over the last few days, it turns out that during my troubleshooting I found a post where someone had a similar issue and they resolved to tweak the spanning tree settings, I followed along and didn't notice any benefit or downside, after looking at my logs like @marce1000 mentioned I noticed that ports were being set to disabled and then being re-enabled multiple times a minute, one of those ports were my uplink.  

This is why everything was working intermittently. Things are fine now and only time will tell. Thank you again @Flavio Miranda and @marce1000 for your help