Can you post the specific config of the Layer 3 interfaces of the two VLANs.....as this sounds very odd.

How many client PC or hosts do you have in each VLAN...is it a classic /24 subnet with typically 250 hosts ?

If you have a very large client PC base in a single VLAN.....i.e 500+ then you could have ARP or DHCP broadcasts on initial bootup causing problems - but not when logging off.

Hello

Thank you very much for your answer

In one lan i have 200 clients aprox and in other 50

This is the config file:

'-----------------------------------------------------------------------------------

!Current Configuration:
!System Description "Dell 48 Port Gigabit Ethernet, 2.1.0.13, VxWorks5.5.1"
!System Software Version 2.1.0.13
!
configure
vlan database
vlan  2-3
vlan association subnet x.x.x.x 255.255.255.0 2
vlan association subnet y.y.y.y 255.255.255.0 3
exit
stack
member 1 2
exit
ip address 192.168.50.5 255.255.255.0
ip routing
ip route 0.0.0.0 0.0.0.0 x.x.x.237
router rip
no enable
exit
interface vlan 2
name "LAN_xxx"
routing
ip address  x.x.x.254  255.255.255.0
no ip proxy-arp
exit
interface vlan 3
name "LAN_yyy"
routing
ip address  y.y.y.254  255.255.255.0
no ip proxy-arp
exit
username "admin" password xxxxxxxxxxxxxxxxxxxxxxxxxx level 15 encrypted
router ospf
no enable
no 1583compatibility
exit
!
interface ethernet 1/g3
switchport access vlan 2
exit
!
interface ethernet 1/g4
switchport access vlan 2
exit
!
...
!
interface ethernet 1/g24
switchport access vlan 2
exit
!
interface ethernet 1/g25
switchport access vlan 3
exit
!
...
!
interface ethernet 1/g48
switchport access vlan 3
exit
exit

'--------------------------------------------------------------------

Thank you very much

 

 

For yor logon issue could i suggets you use this command on each PC /host interface :

 interface ethernet 1/g3

 spanning-tree portfast

By enabling port-fast on each user PC port you will skip the listening learning stages of Spanning tree and go straight to forwarding of

packets.

If you enable port-fast on each of the PC ports, be careful about connecting other switches to those ports or causing a loop in your network.  Port fast effectively disables the benefits of Spanning Tree.  But I agree with Sentinel-master, you will see a decrease in the amount of time it takes before each of your PCs are able to send and receive packets when the NIC links up initially.

But I have a feeling that the type of latency that you're talking about might be different.  Can you give a hypothetical scenario that describes your problem?  When you're seeing packet loss, are you seeing that on the host computers when doing pings or is your switch showing something indicating dropped packets or errors in its counters?

One other thought I had related to PCs, is the default gateway, just want to check this piece of information from you.

How have you assigned IP addresses to your PC hosts....is it via DHCP or static IP addressing.

Either way what is the default IP gateway address of teh PC hosts ?

.....is it the LAN IP address of the L3 switch interface ?

Hello tester25

Thank you for your answer

I see the packet loss when i do a ping from one vlan1 computer to one vlan2, if i do a ping from vlan1 to vlan1 or vlan2 to vlan2 there is not packet loss.

 

Hello sentinel-master

Thank you very much for your answer

I have DHCP in each vlan. and the gateway for pcs is the vlan ip interface for each vlan.

Regards

Okay that all makes sense -just wanted to make sure there was no other Layer hop or device involved.

Just to test a theory can you do a ping from PC_VLan 2  to PC_VLAN_3 and vice versa - whats the results ?

Avoid ping or using VLAN1 - as I want to see if the default management VLAN is related to loss.

hello sentinel-master

Thank you very much for your answer

I did a mistake in before post. where i said vlan1 to vlan2, i should say vlan2 to vlan3 and vice versa. The result is the same, packet loss at the begin and at the end of work. From vlan2 to vlan2 everything is ok and the same for vlan3

 

Thank you very much

Kind regards

 

This is bad news and is either a firmware bug - or the Layer 3 forwarding performance (between different VLANs) is getting hammered for soem reason.

I noticed in your config you have both RIP & OSPF enable - do you need both these enabled at the same time, could you turn one or both  off just to chekc CPU performance and interface forwarding without them in config.