Advanced Traffic Management Guide K/KA/KB.15.15

When the switch uses a match/ignore statement to compare an IP address and corresponding
mask/prefix length to the IP source/destination address carried in a packet, the IPv4 mask-bit
settings and IPv6 prefix-bit settings select packets in different ways.
• An IPv4 mask length creates a mask in which:
A mask-bit setting set to 0 (off) requires the corresponding bit in a packet's IPv4
source/destination address to be the same binary value as the mask-bit in the matching
IPv4 source/destination address.
•
• A mask-bit setting set to 1 (on) is used as a wildcard and allows the corresponding bit in
a packet's IPv4 source/destination address to be either binary value (0 or 1).
Table 35 How CIDR notation is used with IPv4 SA/DA match criteria
Range of IPv4 addresses selected by the match criteriaResulting maskIPv4
Source/Destination
address used with CIDR
notation in a
Match/Ignore
statement
The leftmost 15 bits must match; the remaining bits are
wildcards.
0.1.255.25510.38.240.125/15
The leftmost 20 bits must match; the remaining bits are
wildcards.
0.0.15.25510.38.240.125/20
The leftmost 21 bits must match; the remaining bits are
wildcards.
0.0.7.25510.38.240.125/21
The leftmost 24 bits must match; the remaining bits are
wildcards.
0.0.0.25510.38.240.125/24
All bits must match.0.0.0.018.38.240.125/32
• An IPv6 prefix-length creates a mask in which:
A mask-bit setting set to 1 (on) requires the corresponding bit in a packet's IPv6
source/destination address to be the same binary value as the mask-bit in the matching
IPv6 source/destination address.
•
• A mask-bit setting set to 0 (off) is used as a wildcard and allows the corresponding bit
in a packet's IPv6 source/destination address to be either binary value (0 or 1).
Table 36 How CIDR notation is used with IPv6 SA/DA match criteria
Range of IPv6 addresses selected by the match
criteria
Resulting maskIPv6 source/destination
address used with CIDR
notation in a Match/Ignore
statement
The leftmost 64 bits must match; the remaining
bits are wildcards.
FFFF:FFFF:FFFF:FFFF::2001:db8:0:7::5/64
The leftmost 72 bits must match; the remaining
bits are wildcards.
FFFF:FFFF:FFFF:FFFF:FF00::2001:db8:0:7::5/72
The first 126 bits mst match; the C value in the
mask allows four possible combinations (D37C,
FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFC2001:db8::244:17ff:feb6:d37d/126
D37D, D37E, and D37F) in the last block of a
matching IPv6 address.
All bits must match.FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF2001:db8:0:7:af:e2:c1:5/128
370 Classifier-based software configuration