SG350 28 Port Internet Connectivity

[syntech]

Hello ,

I am a new user .

I am trying to work on 2 scenarios with SG350 L3 switch.

Scenario - 1

I am trying to terminate WAN conection on on one of the Fiber port of the switch. ISP box is connected to SG350 via fiber patch

My ISP gives /31 public address to be configured on CPE ( which is my SG350 Switch) 

I have tried to confiure Gi port 25 to layer 3 port and assign IP address with /31 mask however I am getitng error message - Illigal mask. So I am not sure what I am doing wrong here ? Does this model support /31 mask ?

Scenario - 2

I am trying to terminate MPLS conection on the SG350 L3 Switch. MPLS provider provides /30 subnet with vlan tagging 101

I have configured my Gi25 port as L3 assign an IP address and then try to issue command encapsulation dot1q 101 on the Gi25 port however it is not taking this command.

Can youplease advice if I am misisng anything.

Again Objective is to terminate MPLS link on this Layer 3 switch port and then ceck the conenctivity.

TIA

[balaji.bandi]

Sen -1 

Try /30  because /31 is host entry.

Sen 2 :

2 Options 

1- You can configure the port as an access port with 101

configure VLAN 101 with IP address provided by the provider

2. if you looking to have trunk

make Port as Trunk and allow VLAN 101 also make native vlan as 101

configure vlan 101 interface with IP address.

https://www.cisco.com/c/en/us/support/docs/smb/switches/cisco-350-series-managed-switches/smb5827-configure-vlan-interface-settings-on-a-sx350-sg350x-or-sx550.html

any of the Case these are switches, can not do any nat address translation, so we need to bare in mind.