MOC: Addressing and Routing Plan for EaStMAN Phase I and II
MOC: Addressing and Routing Plan for EaStMAN Phase I and II
Author: Sam Wilson/George Howat
Version: 1.9, 28/8/97 GH: - tweaked description of initial router
config for non-FDDI ring routers
Version History
The possible consequences of attaching an institution at multiple points on the Phase II network are also indicated.
Ed Old College 194.81.56.65 oc2.ed.eastman.net.uk 60001 Ed Pollock 194.81.56.66 ph2.ed.eastman.net.uk 60002 Ed New College 194.81.56.67 nc2.ed.eastman.net.uk 60003 MHIE Cramond 194.81.56.77 gw2.mhie.eastman.net.uk 60011 MHIE Holyrood 194.81.56.78 gw1.mhie.eastman.net.uk 60010 ECA Grassmarket 194.81.56.81 gw1.eca.eastman.net.uk 60020 ECA Lauriston 194.81.56.82 gw2.eca.eastman.net.uk 60021 QMC Leith Links 194.81.56.10 gw2.qmced.eastman.net.uk 60031 QMC Corstorphine 194.81.56.94 gw1.qmced.eastman.net.uk 60030 Napier Merchiston 194.81.56.97 me1.napier.eastman.net.uk 60040 Napier Sighthill 194.81.56.98 si1.napier.eastman.net.uk 60041 Heriot-Watt 194.81.56.110 gw1.hw.eastman.net.uk 3198 SuperJANET 194.81.56.126 gw1.sj.eastman.net.uk 786
Note changes from previous issue for gw2.mhie and gw2.qmced.
The IP addresses are not selected in an arbitrary fashion, the partitioning allows various options for future expansion.
The netmask is 255.255.255.0 but the choice of addresses above allows scope to change this later if necessary, e.g. to 255.255.255.192 or into even smaller subnets. The exact basis for the allocation is given as an Appendix.
An example of the cisco 4500/4700 configuration commands for the FDDI interface on the Old College router is:
description --- MAN FDDI interface at Old College
interface fddi0
ip address 194.81.56.65 255.255.255.0
The IP addresses of the interfaces connecting to site LANs are of
course assigned according to local policy using similar commands for
the various ethernet etc interfaces (eth0, eth1, ... fddi1)
Note also the MAN autonomous numbers. Two of these, Heriot-Watt and SuperJANET are the particular values previously in use on those networks.
In Phase I of the MAN, Edinburgh and Napier each have a Class B address split across the MAN. Edinburgh's setup is covered under `Site Routing' below, and Napier needed to re-address one half of their bridged central network to change to using the MAN. (Note: done at 23rd August.) In Phase II, it seems likely that QMC will become attached to the MAN at two sites. This implies that they will have to re-address part of their network, since the internal structure of their network becomes relevant to the IP subnetting at that time.
NOTE: the QMC situation is generally true when an institution becomes multiply attached to the MAN.
Version 4 of BGP includes explicit netmasks for classless routing which allows the Ed and Napier Class B networks to be split across the MAN. The `E....' means external and refers to a particular way of configuring the protocol. Each site is assigned a fake Autonomous System (AS) number shown in the Table, and peers with one or more other routers acting as route servers. The Edinburgh, SuperJANET and Heriot-Watt routers have been co-opted as the route servers.
NOTE: The SuperJANET SMDS service uses BGP in the same way as this, and it also has the advantages that it gives us a high degree of control over the way routing is handled. It is also vendor independent.
The IPX network number will be C25138. This is the first three bytes of the MAN IP network address expressed in hexadecimal and is therefore compatible with Novell's worldwide network number registry.
The currently preferred method is to use a native FDDI encapsulation for IPX (default for Cisco FDDI is SNAP encoding - Fddi_Snap in Novell-speak) but to use Cisco's EIGRP rather than IPX RIP and SAP to carry routing and service information. Edinburgh and Napier will run EIGRP with different Autonomous System numbers which will effectively partition the MAN IPX network into two separate and disconnected domains.
This scheme has worked well but there are several levels of fallback from this position should problems have arisen during testing and implementation:
In Phase II where it seems that QMC may become multiply connected to the MAN, there is a possible need to carry DECnet Phase IV and some bridged traffic across the MAN. Whilst this requires a little further study, it seems likely that a solution will involve encapsulation of bridged traffic using Cisco's GRE protocol, but it may be possible to carry separate DECnet domains on the MAN simply by making sure that different area numbers are used and that none of the MAN routers is configured as a level-2 (inter-area) router.
Both Edinburgh College of Art and Moray House have plans in Phase II to attach their other campuses, Lauriston and Cramond, respectively. This will not cause any major upheaval as at QMC and Napier, since they will ensure that in the implementation of their Phase I addressing changes, they will be able to assign different subnet groups to each campus.
hostname Each router is given a convenient name for identification and documentation. These are shown as the little-end of the fully qualified EaStMAN name in the Table. For example, for Old College:
hostname oc2.ed
snmp-server community This must be set to a known to a specific value for use by the network management system(s) on the MAN. To aid in auto discovery, the read-only value ""public" is used. The configuration of the IP addresses of hosts which will receive snmp traps is also required:
snmp-server community public RO
snmp-server host 129.215.166.18 snmp
The address 129.215.166.18 is the address of the NMS system employed by
the MOC to monitor the network. Note also that on the cisco routers we
can easily restrict access to a list of IP addresses on the MAN. This
may be a desireable condition.
boot host At 26rd August 1995, the files and systems required to boot the router currently reside in the Edinburgh EdLAN network. For example, at gw1.qmced we have:
boot host /edlan/eastman/gw1.qmced 129.215.38.17
boot host /edlan/eastman/gw1.qmced 129.215.166.17
Note the change from previous issues of the document - routers are
in the process of being updated as reconfiguration is required.
This command is issued twice (can be more) to supply a list of possible sources for the boot file. An example might be: the MOC NMS, a backup system, a system local on the site. Each site wishing to take the responsibility for the host file needs to nominate a potential host for this service, the requirements are to support the tftp file transfer protocol employed by the router while booting from the network. If wishing to do this locally, then please inform the MOC for discussion - there are security issues involved in this procedure.
An outline of this process follows:
The minimum information required to start the configuration process is to configure the FDDI or ethernet interface (fddi0 or fddi1 depending on how the single- and multi-mode interfaces have been installed, eth0 etc for ethernet) with an IP address and a mask, a route to where the initial configuration is held for startup (at least), and the name of that file.
A captured typical session to configure the global parameters follows as an example, some discussion follows. After global configuration there are some specifics.
Configuring global parameters:
Enter host name []: nc2.ed
Enter enable password []: whatever-selected
Enter virtual terminal password []: whatever-selected
Configure SNMP Network Management? []: yes
Community string []: public-as-selected
Configure DECnet? []: no
Configure AppleTalk? []: no
Configure IPX? []: no
Configure bridging? []: no
Configure IP? []: yes
Configure IGRP routing? []: no
Configure RIP routing? []: no
Configuring interface parameters:
Configuring interface Ethernet0:
Is this interface in use? []: no
Configuring interface Ethernet1:
Is this interface in use? []: no
Configuring interface Fddi0:
Is this interface in use? []: yes
Configure IP on this interface? []: yes
IP address for this interface []: 194.81.56.67
Number of bits in subnet field []: 0
Class C network is 194.81.56.0, 0 subnet bits; mask is 255.255.255.0
The following configuration command script was created:
---- script displayed .. omitted here.
Use this configuration? [yes/no]: yes
Discussion:
Number of subnet bits
enter the value 0 (zero). The IP address for the MAN interface, fddi0,
is to be taken from the Table, and the subnet mask
is 255.255.255.0, i.e. the default for a class C network).
After the global configuration is complete, we need to set up some access to the more complete configuration held in a file on holyrood.ed.ac.uk. This will be employed for access to the router to configure via download etc.
conf t
ip route 129.215.0.0 194.81.56.65
^Z
(^Z means Ctrl+Z). This adds a route to the Edinburgh network via the
Old College router on the MAN; for cases where the router is not on the
main FDDI MAN network, this would be the address of the appropriate
gateway which would allow access to/from Edinburgh's network. Note that
after the reboot described below, this static route is turned off again.
Next type:
conf net
This command results in the series of prompts as:
Host or network configuration file [host]? Address of remote host [255.255.255.255]? 129.215.166.17 Name of configuration file []? /edlan/eastman/< filename > Configure using /edlan/eastman/< filename > from 129.215.166.17? [confirm] y ^Z< filename > is the name of your router (see the Table for the part preceding the eastman.net.uk). The responses shown are < CR=default >, holyrood.ed.ac.uk is the boot host. For Sighthill, the router configuration filename would be /edlan/eastman/si1.napier.
write mem
Type the command: reload
or
Power cycle the router
sh ip route
sh ip bgp
should display routes being built up from the information in the new
configuration. You should also be able to telnet to any of the
other routers (or to any host through the Old College router).
conf t
no ip route 129.215.0.0 194.81.56.65
^Z
The numbering scheme is extremely conservative. In essence the network is first divided into 4 subnets with host number ranges 0-63, 64-127, 128-191 and 192-255. We then assume the classical IP restriction that the first and last subnets are unusable and thus we number in the range 64-127. Again if this were really a subnet the first and last host numbers would be reserved so we may use from 65 to 126.
----------------------------------------- 0 : reserved (possible subnet zero) 63 ----------------------------------------- 64 reserved (possible zero host) : : host range 65-126 usable : 127 reserved (possible all-ones host) ----------------------------------------- 128 : reserved for future expansion 191 ----------------------------------------- 192 : reserved (possible all-ones subnet) 255 -----------------------------------------
In allocating numbers this way we reserve 3 other 64-address subnets for use on other parts of the MAN should we need them.
We then further divide range 64-127 into 8 equal blocks of 8 numbers and assign them to the MAN insitutions and SuperJANET, seven allocations and one spare. We make the further extremely conservative assumption that the first and last address in each block should be reserved and finally we use the numbers in alternate blocks from opposite ends - the first numbering up from the low end, the second down from the high end - giving maximum flexibility for adjusting the size of allocation to each Institute. (An alternative view of the numbering is of 4 blocks with the first and last numbers reserved and two institutions allocated to each block, numbered from opposite ends.)
Thus the allocation looks like this:
----------------------------------------- 64 reserved 65 first Univ of Ed host : 70 last Univ of Ed host 71 reserved ......................................... 72 reserved 73 last MHIE host : 78 first MHIE host 79 reserved ----------------------------------------- 80 reserved 81 first ECA host : 86 last ECA host 87 reserved ......................................... 88 reserved 89 last QMC host : 94 first QMC host 95 reserved ----------------------------------------- 96 reserved 97 first Napier host : 102 last Napier host 103 reserved ......................................... 104 reserved 105 last H-W host : 110 first H-W host 111 reserved ----------------------------------------- 112 reserved 113 first spare institution host : 118 last spare institution host 119 reserved ......................................... 120 reserved 121 last SJ host : 126 first SJ host 127 reserved -----------------------------------------
Version: 1.7, 27/5/96 GH: add Phase II FDDI IP addresses for ECA/MHIE/QMC
Version: 1.8, 26/8/96 SW: - change Phase II FDDI IP addresses
- describe how AppleTalk is actually done
- update bootfile locations and initial
boot procedure
- add Appendix describing how IP addresses
are allocated
- tidy up this and that
