Definition of a node and a line with specification of the subnet mask and the local IP address.
The two sample definitions below lead to the same result. The class C network can only be further restricted by specifying the subnet mask. The standard subnet mask of a class C network is 255.255.255.0. Specifying a faulty subnet mask (e.g. 255.255.255.244) leads to the standard subnet mask.
/CREATE-NODE NODE-NAME=NORMANOD, -
/ IP-SUBNET-MASK=255.255.255.244
/CREATE-LINE LINE-NAME=NORMALAN, -
/ IP-ADDRESS=192.168.200.5, -
/ L2-PROTOCOL=*CSMACD(NODE-NAME=NORMANOD, -
/ WRITE-DEVICE=ZC,READ-DEVICE=ZB)
In the following, BCAM ignores the specification of the subnet mask in this initial configuration because it does not fit in with the classful routing of a class C network (IP address 192.168.200.5). BCAM assumes the appropriate standard subnet mask of a class C network (255.255.255.0 instead of 255.255.252.0). An “enlargement of the network” is, as could be assumed, excluded with this definition method.
/CREATE-NODE NODE-NAME=NORMANOD, -
/ IP-SUBNET-MASK=255.255.252.0
/CREATE-LINE LINE-NAME=NORMALAN, -
/ IP-ADDRESS=192.168.200.5, -
/ L2-PROTOCOL=*CSMACD(NODE-NAME=NORMANOD, -
/ WRITE-DEVICE=ZC,READ-DEVICE=ZB)
A new result compared to the definition which could be specified with previous BCAM means is obtained by slightly modifying the existing definition.
The adjusted CIDR notation of the subnet mask for the node and specifying the prefix length in the IP address can also enable an “enlargement of the network which is to be operated” to be achieved:
/CREATE-NODE NODE-NAME=NORMANOD, -
/ IP-SUBNET-MASK=255.255.252.0/22
/CREATE-LINE LINE-NAME=NORMALAN, -
/ IP-ADDRESS=192.168.200.5/22, -
/ L2-PROTOCOL=*CSMACD(NODE-NAME=NORMANOD, -
/ WRITE-DEVICE=ZC,READ-DEVICE=ZB)
Diagnosis
The control block information generated can in all cases be displayed using the ASTRID program.
/START-ASTRID
SO
RS CB=(NODE,LINK)