I've been having some performance issues with one of my Cisco switches for a while now. I originally posted on Reddit seeking some help. Now that the issue continues, I wanted to see if anyone had some ideas over here.
I'm using a Cisco 3560G to handle some basic vlans/routing for a rack of servers. The switch has a gigabit uplink and I've recently only been getting a few MBps from external tests to various local servers as well as internally between systems across vlans.
My original configuration had a lot of secondary addresses on various vlans, after discovering that this wasn't best practice - I've offloaded a lot of the addressing for each vlan to a small ER-X. Unfortunately, that hasn't fully corrected the issue.
Here's my current config: https://pastebin.com/raw/dYaZ6q22
Any thoughts/advice would be appreciated!
just a few things I can think of:
You don't need the default-gateway, since you already have ip routing enabled and a default route. So remove this line:
--> no ip default-gateway 18.104.22.168
Also, check if CEF is enabled.
The access ports are typically configured with 'spanning-tree portfast', you might want to add this:
switchport access vlan 542
switchport mode access
Regarding STP, beside portfast on access ports, you should configure rapid PVST on all switches in domain.
spanning-tree mode rapid-pvst
According to configuration - summarize all routes since next hop is the same address:
ip route 22.214.171.124 255.255.255.248 126.96.36.199 ip route 188.8.131.52 255.255.255.248 184.108.40.206 ip route 220.127.116.11 255.255.255.224 18.104.22.168 ip route 22.214.171.124 255.255.255.255 Null0 ip route 126.96.36.199 255.255.255.224 188.8.131.52 ip route 184.108.40.206 255.255.255.248 220.127.116.11 ip route 18.104.22.168 255.255.255.248 22.214.171.124 ip route 126.96.36.199 255.255.255.248 188.8.131.52 ip route 184.108.40.206 255.255.255.248 220.127.116.11 ip route 18.104.22.168 255.255.255.248 22.214.171.124 ip route 126.96.36.199 255.255.255.248 188.8.131.52 ip route 184.108.40.206 255.255.255.248 220.127.116.11 ip route 18.104.22.168 255.255.255.224 22.214.171.124 ip route 126.96.36.199 255.255.255.248 188.8.131.52 ip route 184.108.40.206 255.255.255.248 220.127.116.11 ip route 18.104.22.168 255.255.255.240 22.214.171.124 ip route 126.96.36.199 255.255.255.248 188.8.131.52 ip route 184.108.40.206 255.255.255.248 220.127.116.11 ip route 18.104.22.168 255.255.255.240 22.214.171.124
I've set rapid PVST on the switch. Hopefully this helps.
With regards to the routes - are you simply referring to combining routes? For example, taking two /29 subnets that are currently routed separately and routing them all together as a single /28?
Thanks for the reply! I've removed the default gateway entry. 'ip cef' returns incomplete command, perhaps it's not enabled. Is this something I should consider enabling?
I still need to look into configuring each access port with spanning tree portfast.
ip cef ? distributed Distributed Cisco Express Forwarding linecard CEF linecard commands load-sharing Load sharing optimize Optimizations traffic-statistics Enable collection of traffic statistics
Can also you post -
sh process cpu sort
show spanning-tree detail | in is|top|tran|Link|BPDU:
sh int | in tx|rx|drops|error
There is a lot of output drops on some interfaces. QoS or congestion avoidance (WTD) should be implemented. Implementing WTD would be fastest and it would prevent TCP global synchronization issue.