Installation guide

10-16
Device Manager Guide, Cisco ACE 4700 Series Application Control Engine Appliance
OL-26645-02
Chapter 10 Configuring Network Access
Configuring Virtual Context VLAN Interfaces
Min. Fragment MTU Value Enter the minimum fragment size that the ACE appliance accepts for
reassembly for a VLAN interface.
• For IPv4, valid entries are 28 to 9216 bytes. The default is 576.
• For IPv6, valid entries are 56 to 9216 bytes. The default is 1280.
Action For IP Header
Options
Select the IPv4, IPv6 or both action the ACE appliance is to take when
an IP option is set in a packet:
• Allow—Indicates that the ACE appliance is to allow the IP packet
with the IP options set.
• Clear—Indicates that the ACE appliance is to clear all IP options
from the packet and to allow the packet.
• Clear-Invalid—Indicates that the ACE appliance is to clear the
invalid IP options from the packet and then allow the packet. This
action is the default for IPv4.
• Drop—Indicates that the ACE appliance is to discard the packet
regardless of any options that are set. This action is the default for
IPv6.
Enable MAC Address
Autogenerate
Allows you to configure a different MAC address for the VLAN
interface.
Min. TTL IP Header Value Enter the minimum number of hops a packet is allowed to reach its
destination. Valid entries are integers from 1 to 255. This field is
applicable for IPv4 and IPv6 traffic.
Each router along the packet’s path decrements the TTL by one. If the
packet’s TTL reaches zero before the packet reaches its destination, the
packet is discarded.
MTU Value Enter number of bytes for Maximum Transmission Units (MTUs). Valid
entries are integers from 68 to 9216, and the default is 1500.
Enable Syn Cookie
Threshold Value
Embryonic connection threshold above which the ACE applies
SYN-cookie DoS protection. Valid entries are integers from 1 to 65535.
Action For DF Bit Indicate how the ACE appliance is to handle a packet that has it DF
(Don’t Fragment) bit set in the IP header:
• Allow—Indicates that the ACE appliance is to permit the packet
with the DF bit set. If the packet is larger than the next-hop MTU,
ACE appliance discards the packet and sends an ICMP unreachable
message to the source host.
• Clear—Indicates that the ACE appliance is to clear the DF bit and
permit the packet. If the packet is larger than the next-hop MTU, the
ACE appliance fragments the packet.
The default is Allow.
Table 10-3 VLAN Interface Attributes (continued)
Field Description