AVR web interface "Error 403 Access forbidden" via Cisco, directly to PC working fine

[Oblivion_Tech]

Hi all,

I have an issue with AVR (Marantz SR-6012) web interface access.

If an AVR is connected directly to the laptop, web interface is working fine.

But if I plug an AVR and a laptop to the same VLAN (setup includes Cisco Core Switch 4500x and multiple Cisco distribution switches 9300), I'm getting a message "Error 403: Forbidden, Access forbidden" while trying to access the same web interface. It's interesting I can normally ping an AVR from the laptop, once it's connected to the Cisco switch, but just cannot access a web interface.

There is an another model of the AVR (Marantz 7012) that is working just fine, connected directly or connected to the Cisco switch (this model uses port 10080 if that helps).

[pieterh]

first check your proxy settings on the pc

if directly connected to the AVR, the proxy cannot be reached, so all packets are sent to the AVR

if connected tot the VLAN it can be reached and may interfere -> you may need to add an exclusion to the proxy settings for this AVR

[Oblivion_Tech]

Hi Pieterh,

Use a proxy server setting is OFF and if I enable it and add an AVR address as an exclusion it doesn't change a single thing. I can still ping the unit, but cannot access it having "Error 403: forbidden" message.

[pieterh]

ok clear, proxy is not the culprit 

first make sure the address is not in use on another device

-> open the url when the Marants is not connected to the 4500 and the laptop is

a bit more information on the 4500 network will also help,

there may be access-lists and other security measures involved in this network

[Georg Pauwen]

Hello,

is the Marantz using DHCP, or do you have a static IP address assigned ? What is the 'Router Access' status on the 'Diagnostics' page ?

http://manuals.denon.com/AVRX2600H/EU/EN/HJWMSYjencafmg.php 

[Oblivion_Tech]

Hi Georg,

DHCP is off, I've manually set IP address, including the gateway (router address). Gateway is a VLAN address and it works fine for all other devices within the VLAN including another AVR which I can access, so I don't think it's related to that.

But it's definitely related to Cisco as directly connected it works fine while if connected through the Cisco, Forbidden 403 message appears.

[Georg Pauwen]

Hello,

this one is going to be tough to resolve...

Can you find out if the 9300 or the 4500x is the problem, or both, by connecting the laptop directly to the 4500x ?

[Oblivion_Tech]

Hi Georg,

I'd say this is something with a Cisco configuration, but I'm not sure of course.

As written above, if I connect a laptop directly to the AVR unit, I can normally ping an AVR and access its web interface. So I'd exclude an AVR as a problem.

Connecting an AVR to the Cisco switch, to be more precise to the certain port configured to the vlan 500 (e.g.) and then connecting a laptop to another port with the same vlan 500, I can normally ping an AVR, but I cannot access a web interface having "Error 403: Forbidden, Access forbidden". I've tried deleting cookies, another browser, another laptop, etc. 

I'm confident there is something to be configured on the Cisco switch.

[Georg Pauwen]

Hello,

so even with both the AVR and the laptop connected to the same Vlan, on the same switch, the problem persists...

I guess it is safe to assume that the switch(es) is/are the problem. Maybe the Marantz uses some sort of discovery protocol. Try and enable 'lldp' on the switch(es):

9300#conf t

9300(config)#lldp run

[pieterh]

there is still little information about the network setup

did you check any logs in the network?