HomeRouting Service

Subnet Routing Service

At present, laboratories have a device to perform routing in their subnets, but this function will be provided by the IMC.

Routing service

The IMC will carry out routing for networks. Labs can save the trouble of installing a router.
* Please note that we will not provide NAT functions. If you use a private network, you need to continue having a router.

  • Routing: to find an optimal path of information or data streams from the source to its destination
  • NAT: technology that enables multiple computers to share a single global IP address

Service Content

  • Routing
  • Filtering
  • DHCP server
  • VLAN configuration (Two or more rooms can be connected in the same network.)


For routing for 133.15.x.0/25, the default gateway IP address is 133.15.x.1..
Do not use the IP address of 133.15.x.1 to 5, which will be used by the IMC.


A filtering class is determined by default, depending on the range of IP addresses.
Assign IP addresses in a subnet on the basis of the classes needed.

Filtering classes and applicable range of IP addresses

(Divided into: outgoing from the subnet and incoming to the subnet)

  • The IP addresses of 1~5 (133.15.x.1~5) are not allowed to be used.
  • Class 1: 1:6~95 (133.15.x.6~95)
    • Outgoing: No restrictions inside and outside the University
    • Incoming: No restrictions for receiving data from within the University; to receive data from outside, it is necessary to apply for server registration.
  • Class 2: 96~126 (133.15.x.96~126)
    • Outgoing: Data cannot be transmitted to outside the subnet.
    • Incoming: Data cannot be received from outside the subnet.
    • This filtering class is suited for a server, etc. set for sending and receiving data within the subnet.

DHCP server

The IP addresses assigned by DHCP by default are as follows:

  • Range of IP addresses assigned by DHCP: 133.15.x.64 to 95
  • Lease time: 1 hour

If you apply for filtering services at the same time, Class 1 will be used for IP addresses assigned by DHCP.


If you have any requests, as shown below, please feel free to contact us.

  • Want to receive data from selectively selected IP addresses/subnets within the University
  • Want to increase the number of units with IP addresses assigned (Want to change a subnet mask)
  • Want to change the range of IP address in the filtering settings

How to apply

Please send the following information required for application to the e-mail address below.

  • Subnet address (If you are a subnet user)
  • Filtering: Used / Not Used
  • DHCP server: Used / Not Used
  • The number of the room in which VLAN settings are configured

* If you need to apply for a subnet, please file an application at the same time as applying for subnet connections.

Where to apply
* Please put at the end of the e-mail address.