Inter vlan routing issue with procurve 1920-24G

[Allen Zhao_1]

We are trying to implement vlan on several 1920-24G switches, but I think we are seeing inter-vlan routing issue. 

Here is the set up (since there is no useful cli output, I have to be wordy):

We have a default subnet in 192.168.100.0/24, we have some ports untag as 50 on several switches' select ports, so that PC connecting to these ports will be on 192.168.50.0/24 subnet.

All the switches involved have VLAN Interface configured in both 100.0/24 and 50.0/24 subnet. The network is in star topography: 

a) Star center:  

default gateway: 192.168.100.237 (this is our firewall IP)

vlan interface: 192.168.100.4/24 | 192.168.50.1/24

IPv4 routing (mostly created by VLAN Interface create):

destination                mask                                protocol    priority    Next Hop                            Interface

0.0.0.0                         0.0.0.0                             static          60              192.168.100.237           Vlan-interface1

127.0.0.0                   255.0.0.0                         direct         0                 127.0.0.1                           InLoopBack0

127.0.0.1                   255.255.255.255         direct         0                 127.0.0.1                           InLoopBack0

192.168.50.0           255.255.255.0              direct         0                 192.168.50.1                   Vlan-interface50

192.168.50.1           255.255.255.255         direct         0                 127.0.0.1                           InLoopBack0

192.168.100.0        255.255.255.0              direct         0                 192.168.100.4                 Vlan-interface1

192.168.100.4        255.255.255.255         direct         0                 127.0.0.1                           InLoopBack0

b) All satelites (total 5 of them):

default gateway: 192.168.100.4 (the IP of the star switch)

vlan interface: 192.168.100.xxx/24 | 192.168.50.yyy/24

The IPv4 routing is similar to above, except the default gateway line:

destination                mask                                protocol    priority    Next Hop                            Interface

0.0.0.0                         0.0.0.0                             static          60              192.168.100.4               Vlan-interface1

We have no other QoS configured. 

The initial implementation is half success, we have no issue between devices within 192.168.100.0/24, or within 192.168.50.0/24 subnet.

The pinging between the 2 subnets, however, show some packet dropping, anywhere from 0% - 20% loss.

What could be the issue here?

[Vince-Whirlwind]

What is the IP address & default GW on the hosts that are trying to ping each other?

Why do the "satellite switches" have an interface in both VLANs?

[Allen Zhao_1]

The devices connecting to these switches can be either on 100.0/24 or on 50.0/24 depending on the port vlan tag. 

For the devices with IP in 100.0/24, the gateway is uniformly 192.168.100.4, and for the devices wth IP in 50.0/24, the default gateway is uniformly 192.168.50.1

As I have mentioned, the pinging between hosts that are in the same vlan have no issues, even when they are on different switches. The packet loss is only for inter-vlan.

Why do the "satellite switches" have an interface in both VLANs?

We thought we need both, because within the switch, we need to allow routing between devices that are in different vlan?

Do you see problem there?

[Vince-Whirlwind]

The satellite switches shouldn't be doing any routing, that's what the "star centre" switch is for.

I'm not sure what would cause the packet loss, precisely, but the extra IP interface on the satellite switches won't be helping, it might even be confusing things.

[16again]

The "star centre"  (=core) switch can only handle wire speed routing for up to 60 mac addresses.

Get a beefier core switch.  A HP1920-48G can handle 256 addresses. ....or a "higher end" L3 switch

An alternative is bringing L3 routing to the "satellite" (=access) switches, creating a full L3 topology. 

Setup:

Core switch:

  VLAN 100  192.168.100.4/24

  VLAN50     192.168.50.1/24

   VLAN 201    10.0.201.254  (Link access1)

   VLAN 202    10.0.202.254  (Link access2)

   VLAN 203   10.0.203.254  (Link access3)

   VLAN 204   10.0.204.254  (Link access4)

   VLAN 205    10.0.205.254  (Link access5)

Access1

  VLAN 101  192.168.101.1/24

  VLAN51     192.168.51.1/24

  VLAN 201    10.0.201.1/24  Uplink

Access2

  VLAN 102  192.168.102.1/24

  VLAN52     192.168.52.1/24

  VLAN 202    10.0.202.1/24  Uplink

.......

That's what L3 access switch is for!