Cisco 3750G-12S-S issue when connect with Coral DSLAM when create vlan tagging in DSLAM

[csawest.dc]

Dear Experts,

We are using Cisco WS-3750G -12S-S  Switch.

We are facing problem when connect CORAL Telecom DSLAM with Cisco 3750 switch.

We are using also Coral DSLAM 48 ports

We are configued from port 1 to 48 port saprate VLAN in CORAL DSLAM ( port 1 vlan 101 , port 2 vlan 102 upto 48 port vlan 148)

Our Scenario as bellow :

My Laptop connect >>> ADSL Modem >>> Coral DSLAM port 2 >>>Coral DSLAM uplink port connect >>> Cisco 3750 port 2

when configure vlan 102 on Coral DSLAM port 2 and my 3750 switch port 2 vlan 102  ,  i am not able to communicate with my switch vlan 102 ip
but when i remove vlan 102 from Coral dslam port 2 then i am able to ping.

and when my lapto connect >>>> ADSL Modem >>> Coral DSLAM port 2 >>>>Coral DSLAM uplink connect with normal Server

that time all the vlan tagging communicate wit h my server ip from my laptop.

Their Senior Engg told us you need to vlan policy create or mapping then u can able to ping

So what is the issue and how can i solve this

Please help me it;s very URGENT for me.

Many Thanks in ADV,

[Karel Vins]

Hi,

are you sure that traffic from CORAL DSLAM uplink is tagged?

What is your configuration on 3750 port?

Regards,

Karel V.

[csawest.dc]

Dear Karel,

first of all thanks for your support.

Because it's very tough for me to solve this issue.

Yes Coral DSLAM uplink taggad we confirm with their Engineer.

Switch-3750(config)# int gi1/0/2

desc *** Connect to Coral DSLAM ***

Switchport mode access

Switchport access vlan 102

int vlan 102

ip add 192.168.1.1 255.255.255.0

Coral DSLAM port 1 to 48 vlan 101 to 148 ok

My Laptop connect with coral DSLAM port 2 vlan 102 ok

ip of my laptop 192.168.1.2 255.255.255.0 gatway 192.168.1.1

when i ping from my laptop 192.168.1.1 unable to ping but when i remove vlan 102 from coral dslam port 2 then i am able to ping

Our Scenario

Billing Authentication Server>>> Cisco 3750 port 1 >>>> cisco 3750 port 2 >>>> Coral DSALM uplink port >>> Coral DSlam dsl port 2 >>> ADSL Modem >>> my Laptop

we need to communication billing authen server from my laptop and even all the DSLAM port 1 to 48 need to communicat with billing authen server which is connect with Cisco 3750 port 1.

and we configure all the DSLAM port 1 to 48 vlan 101 to 148

So in this setuation what kind of configuration we need to configure in Cisco 3750 to communicate all the DSLAM port to communication with Billing Authentication Server when DSLAM port 1 to 48 configured ( vlan 101 to 148)

Thanks once again

[Karel Vins]

You have to set 3750 port to mode trunk and encapsulation dot1q.

Port in mode access accept only untagged packet.

Karel V.

[csawest.dc]

Dear Karel,

You mean to say we need to configure both the ports ( port1) connect with Billing Authentication Server and port 2 connected with Coral DSLAM we need to configure encapsulation dot1q and trunk both the port of Cisco 3750 but my billing Authentication Server not support 802.1q their NIC not support and also if Coral DSLAM not support encapsulation dot1q and trunk so what should i do how can achive  as per my require. any other solution to achive my goal ??

Thanks in ADV,

[Karel Vins]

In what VLAN is your authentication server? Your server facing port must be configured as access port in that VLAN.

You said: "Yes Coral DSLAM uplink taggad we confirm with their Engineer."

If traffic from Coral DSLAM uplink is tagged (it probably means that it uses dot1q encapsulation), you need to set your switch port 2 as trunk to allow it receiving tagged packets.

[Karel Vins]

As first step, you can try this config:

My Laptop connect >>> ADSL Modem >>> Coral DSLAM port 2 >>>Coral DSLAM uplink port connect (tagging with VLAN102 tag) >>> Cisco 3750 port 2 (mode trunk, encaps dot1q)

Then you may be able to ping interface vlan 102 ip address.

KV

[Karel Vins]

Alternative solution could be to disable tagging on CORAL DSLAM uplink (if it is posible) and set your port 2 as access port in VLAN 102 (your original config)

BTW: Why you have each port in separate VLAN?