Methods and systems for automatically building an internet protocol (IP) network

A method for automatically building an internet protocol (IP) network, the method comprising:

• at a first switch or router, obtaining a first IP address from a Dynamic Host Configuration Protocol (DHCP) server;
• on an unnumbered interface of the first switch or router, receiving a DHCP request from an unnumbered interface of a second switch or router, wherein each of the unnumbered interface of the second switch or router and the unnumbered interface of the first switch or router comprises an unnumbered logical or virtual interface, and wherein IP processing is enabled on the unnumbered logical or virtual interface without assigning an explicit IP address to the unnumbered logical or virtual interface, wherein the first switch or router, the second switch or router, and at least one other switch or router are connected in series through a plurality of unnumbered interfaces to form a circle, wherein all network interfaces of the second switch or router are unnumbered interfaces;
• at the first switch or router, forwarding the DHCP request from the second switch or router to the DHCP server using the first IP address as a relay IP address;
• at the first switch or router, receiving a DHCP response from the DHCP server, wherein the DHCP response contains a second IP address of the second switch or router, and wherein the first and second switches or routers are in the same subnet, and wherein the first and second IP addresses have an identical subnet mask;
• and
• at the first switch or router, forwarding the DHCP response from the DHCP server to the second switch or router through the unnumbered interface of the first switch or router and the unnumbered interface of the second switch or router.

A network element, the network element comprising:

• memory;
• and
• one or more processors configured to:
• obtain a first IP address from a DHCP server;
• on an unnumbered interface of the network element, receive a DHCP request from an unnumbered interface of a second network element, wherein each of the unnumbered interface of the second network element and the unnumbered interface of the network element comprises an unnumbered logical or virtual interface, wherein IP processing is enabled on the unnumbered logical or virtual interface without assigning an explicit IP address to the unnumbered logical or virtual interface, wherein the network element, the second network element, and at least one other network element are connected in series through a plurality of unnumbered interfaces to form a circle, and wherein all network interfaces of the second network element are unnumbered interfaces;
• forward the DHCP request from the second network element to the DHCP server using the first IP address as a relay IP address;
• receive a DHCP response from the DHCP server, wherein the DHCP response contains a second IP address of the second network element, and wherein the first and second IP addresses have an identical subnet mask;
• and
• forward the DHCP response from the DHCP server to the second network element through the unnumbered interface of the network element and the unnumbered interface of the second network element.