HP 5120 Trunk issue

[raj10101]

Hi All,

I've been using HP procurves since long time never had issue with trunking, But company just recenly replaced our all core switches with HP 5120, and my problem start, I've three location all location we using Cisco for routing and VLAN, Now problem is when I connect HP5120 with Cisco router or CISCO ASA using trunk works perfect without any issue until there is traffic between going, Problem is during off hours there are no traffic and the next morning when any PC try to connect for internet, there is no connectivity to my Gateway(CISCO router/ASA). and the moment I disable and enable vlan in router/ASA all works perfect again. I did not change anything in router config what I only change is our Core Switches from Procurve to HP 5120 and issues start.

My Setup is like this:

Two Core Switches(HP5120), Connect to each Router/ASA on port 24 each, port 23 connected between switches, Port 23,24 config is simple:

#port link-type trunk

#port trunk permit vlan all

And some STP config, That's all., I've having same issue with all three location, At one location where I'm using ASA because there is not off hours but I had issue during setup time, when there were no traffic.

[Apachez-]

"Some" STP config you say?

Did you verify so the STP didnt put the interfaces in some blocking mode?

Also could you paste the interface-config of each device along with complete stp config from each device?

[raj10101]

Apachez,

I'm just using simple STP. My HP5120 are connected to cisco router as a Core Switches and I've HP procurve 2510 connected to HP5120 as Access Switches, Here is my STP config for both HP 5120:

####Configuration on Switch A (Master)
stp enable
stp instance 0 priority 4096
stp config-digest-snooping

interface Ethernet1/0/24 (Port Connected to CISCO R1)
stp config-digest-snooping
stp no-agreement-check

####Configuration on Switch B (standby)
stp enable
stp instance 0 priority 8192
stp config-digest-snooping

interface Ethernet1/0/24 (Port Connected to CISCO R2)
stp no-agreement-check

interface Ethernet1/0/23 (Port Connected to Master Switch)
stp config-digest-snooping

[Vince-Whirlwind]

How are the cores connected to each other?

What is the STP status of the links?

STP shouldn't be blocking either link to the routers, as it shouldn't see the routers as a loop, should it?

How do the routers know which "Core" to send traffic to? Are the cores running VRRP?

I'm pretty sure you'll be better off if you IRF the two "Cores" together.

[raj10101]

Nice Suggestion Vince,

That's what I thouht before buy this HP 5120, The main idea behind buying these 8 HP5120 was to use IRF instead STP, But we got HP5120 JE066A, After buy when I was trying to configure IRF we found that in 5120 Seriease only JE066A doesn't support IRF and I seattled with STP.

Well Let's come to the point, Yes I do using HSRP at Router Level. But Since I don't have much idea about STP, I've just configured basic STP after disappointed with HP. But one thing I would like to mention here is I'm running STP only on core switches(HP5120). I did not enable STP on Procurve Switches, Does it the issue you think?

[Vince-Whirlwind]

I think you need to untangle two things here:

STP/Layer2.

With STP, ask yourself - are there any loops in my topology? If so, then you need STP.

If your Procurves have redundant links to the core, then yes, enable STP, but as you are not seeing broadcast storms (are you?) you probably don't have any loops.

Layer3/routing/redundancy.

This is more likely where your problem is - what layer3 functions are the 5120s performing?

Running HSRP on the Routers doesn't help eny of the Layer2 segments that aren't homed on the routers themselves.

It sounds to me like your problem is an issue with your Layer3/routing being at odds with the contents of your ARP tables.

Do you have a network diagram with interfaces identified, VLANs and IP addressing?

Alternatively, post your 5120 configs here, not just little bits of them (*without passwords).