Cannot Ping Subnets on HP A5500 L3 Switch

[KKA_pat]

I am sitting on 172.26.0.20/24

2 HP A5500 L3 switches sitting on 172.28.0.10/24 & 172.28.0.11/24

HP Switch 1 Default VLAN1 IP:

172.28.0.10 

Subnet Mask: 255.255.255.0

Default Gateway: 172.28.0.1

HP Switch 2 Default VLAN1 IP:

172.28.0.11

Subnet Mask: 255.255.255.0

Default Gateway: 172.28.0.1

I can access any other device on the 172.28.0.x network using its access protocol (HTTP, PING, SNMP, Telnet) from the 172.26.0..x network.

I cannot access my L3 Switch A5500 HTTP, PING or Telnet from the 192.168.1.x network.

The only way I can access the switches is from a device/host located on the 172.28.0.x network using either HTTP or Telnet to either switches IP address.

Can anyone explain why? Thanks in advance

[Vince-Whirlwind]

The other devices on the .28. subnet, what do they use for a default gateway IP address?

Can the two .28. switches ping their default gateway?

[KKA_pat]

Yes it is pinging but l3 switch ip is not pinging from other l3 switch in other subnet.