Routing support on SLMS devices

You can configure the following types of routing on Zhone devices:

DHCP

Dynamic Host Control Protocol (DHCP) is the means for dynamically assigning IP addresses. Configure DHCP in the Configuration / Data Routed / DHCP screen

DHCP also provides a mechanism through which clients obtain configuration parameters such as the default router, the DNS server, subnet mask, gateway address, lease time, as well as the IP address from the DHCP server. When the Zhone device acts as a local DHCP server, it can assign temporary (leased) IP addresses to clients. Each DHCP client sends a request to the Zhone device for an IP address lease. The Zhone device then assigns an IP address and lease time to the client and keeps track of a range of assignable IP addresses from a subnetwork.

Some customers choose to have the same IP address every time their DHCP lease renews. This is known as sticky IP addresses. By default, Zhone devices attempt to assign the same IP address to the same client on DHCP lease renewal.

Zhone devices allow for shared pools of IP addresses. With shared pools supported both on numbered and floating interfaces — ranges of IP addresses can be given to a subnet from a numbered interface (single physical interface) or floating interface (multiple physical interfaces).

Host-based (unnumbered) routing overview

Host-based unnumbered interface routing (also called a floating interface) is the mechanism to give an IP address, not to a physical interface, but a floating logical interface which is associated with the system. Floating IP addresses are created  in the Configuration / Data Routed (or Video Routed) / Connections screen. This floating interface may then be shared with physical interfaces by selecting the Interface button in the Configuration / Data Routed (or Video Routed) / Connections screen.

This type of routing allows a granular allocation of addresses based on the host floating IP address and the available subnetwork addresses. Configure host-based routing in the Configuration / Data Routed / Connections screen. Each host is configured with a reference to a floating IP interface so that when an IP address is added to the routing table for the host, the address is assigned to the host from the floating IP subnet.

For example, a floating host address of 10.10.10.1/24, adds one entry in the routing table for the address 10.10.10.1 and makes available a subnet of 253 addresses for individual route configuration. When a route is added to a host, a new routing table entry is created.

For a host-based route you can also assign VLAN, SLAN, CoS, and sCoS values to the host interface.

Host-based routing uses floating IP interfaces and shared DHCP pools to conserve IP addresses or a static IP address. In host-based routing, subscribers connected to the Zhone device are on the same subnet as the Zhone device floating interface.

Network-based (numbered) routing overview

Network-based routes are configured in the Configuration / Data Routed / Numbered screen to create a numbered IP interface that adds IP network addresses with variable length subnet masks to the routing table.

A numbered interface has an IP address given to the physical interface.

This type of routing allows a single routing table entry to represent many numbered host addresses. However, it does not allow for granular IP address allocation. For example, an interface configured with 10.10.10.1/24 adds just one entry to the routing table for the 10.10.10.0 subnet. All 254 addresses in this subnet are assigned to this interface, regardless of how many addresses in this subnet are actually used. Unlike host-based routing, network based-routing requires numbered IP interfaces on the Zhone device and does not use floating IP addresses. In network-based routing, each host, connected to an interface, is in the same network as the Zhone device numbered interface.

For more information

For more information about routing on Zhone devices see the manuals on the Zhone website http://www.zhone.com/support/manuals/.

October 9, 2011