Terminology, Operating rules, Terminology -18 – HP 2600 User Manual
Page 184: Operating rules -18
Port Status and Basic Configuration
Jumbo Packets on the Series 2800 Switches
Terminology
Jumbo Packet:
On the Series 2800 switches, an IP packet exceeding 1522
bytes in size. The maximum Jumbo packet size is 9220 bytes. (This size
includes 4 bytes for the VLAN tag.)
Jumbo VLAN:
A VLAN configured to allow inbound jumbo traffic. All ports
belonging to a jumbo and operating at 1 Gbps or higher can receive jumbo
packets from external devices.
MTU
(Maximum Transmission Unit): This is the maximum-size IP packet
the switch can receive for Layer 2 packets inbound on a port. The switch
allows jumbo packets of up to 9220 bytes.
Standard MTU:
On the Series 2800 switches, an IP packet of 1522 bytes in
size. (This size includes 4 bytes for the VLAN tag.)
Operating Rules
■
Required Port Speed:
The Series 2800 switches allow inbound and
outbound jumbo packets on ports operating at speeds of 1 gigabit or
higher. At lower port speeds, only standard (1522-byte or smaller) packets
are allowed, regardless of the jumbo configuration.
■
Flow Control:
Disable flow control (the default setting) on any ports or
trunks through which you want to transmit or receive jumbo packets.
Leaving flow control enabled on a port can cause a high rate of jumbo
drops to occur on the port.
■
GVRP Operation:
A VLAN enabled for jumbo traffic cannot be used to
create a dynamic VLAN. A port belonging to a statically configured, jumbo-
enabled VLAN cannot join a dynamic VLAN.
■
Port Adds and Moves:
If you add a port to a VLAN that is already
configured for jumbo traffic, the switch enables that port to receive jumbo
traffic. If you remove a port from a jumbo-enabled VLAN, the switch
disables jumbo traffic capability on the port only if the port is not currently
a member of another jumbo-enabled VLAN. This same operation applies
to port trunks.
■
Jumbo Traffic Sources:
A port belonging to a jumbo-enabled VLAN can
receive inbound jumbo packets through any VLAN to which it belongs,
including non-jumbo VLANs. For example, if VLAN 10 (without jumbos
enabled) and VLAN 20 (with jumbos enabled) are both configured on a
switch, and port 1 belongs to both VLANs, then port 1 can receive jumbo
10-18