| Carl Friedrich Gauß Faculty | Department of Computer Science

IBR Netzwerk

AuthorFrank Steinberg

The following tables show the VLANs and subnets that are currently used in the IBR network.

IP address spaces

  • IPv4 host configuration MUST be done via DHCP. Never use static address configuration!
  • IPv6 host configuration MUST be done via autoconf (preferably) or DHCP (alternatively). Never use static address configuration! services, hosts maintained only by IBR admins, ports and hosts located only in the IBR server room of computer pools G40 and 359 client hosts, registered with LDAP client hosts, registered with LDAP by MAC addresses, but using DHCP IPv4 address pool hosts, DHCP IPv4 address pool's testbed hosts registered hosts with fixed private IPv4 addresses Pis managed by ibr-preppi nodes and BMCs in ibr-misc subnet maintained by DS group UDP clients, via TCP clients, via Subnet for Nico, on ibr-misc for "Praktikum Administration von Computernetzen", via and fe80::5072:19ff:fe57:fd3b SAN, isolated from all other subnets subnet, IPMI, iDRAC, etc. subnet for kvm proxy 10G VLAN (configured as PFC group for RoCE) used by DS

If you consider to use a new IPv4 private subnet for your own work, please talk to Frank to get a unique and documented address prefix (e.g., 10.x.0.0/16).


To be prepared for cases in which VLANs may span multiple floors of our building or even a wider range, VLAN-IDs have to be unique. Therefore, the VLAN ID namespace is managed by the GITZ. The following table lists the VLAN which are currently assigned to IBR:

ibr-core136core services; attachments are restricted to the server room and to hosts which are maintained only by IBR admins
ibr-cip137pools (rooms G40 and 359)
ibr-lab138Lab VLAN (currently not is use, 2016-04)
ibr-misc139major VLAN to which any hosts may connect; almost all ports in IBR rooms are in this VLAN
ibr-mgmt140management VLAN (switches, BMCs, iDRACs)
ibr-roce141VLAN for RDMA over Converged Ethernet (RoCE) which is used by the DS group
ibr-ds142a VLAN to interconnect some servers of the DS group
ibr-san143a VLAN to interconnect iSCSI devices in room 104, 10G-only

IPv6 Routing

Don't worry, if you see multiple IPv6 default routes. As of 2017-02 we really have two routers: The Linux firewall and gateway router advertises itself with "low" priority, while the Mellanox switch/router advertises itself with "high" priority, because it is able to route much faster between the IBR subnets. Just in case, the Mellanox router fails, well behaved IPv6 clients should use the Linux router.

last changed 2019-08-19, 10:55 by Frank Steinberg