跳转至主要内容
  • 快速、轻松地下订单
  • 查看订单并跟踪您的发货状态
  • 创建并访问您的产品列表
  • 使用“Company Administration”(公司管理),管理Dell EMC站点、产品和产品级联系人。

Dell PowerEdge FN I/O Module Command Line Reference Guide 9.10(0.0)

PDF

permit tcp

To pass TCP packets meeting the filter criteria, configure a filter.

Syntax permit tcp { source mask | any | host ip-address} [ bit] [ operator port [ port]] { destination mask | any | host ip-address} [ bit] [dscp] [ operator port [ port]] [count [byte]] [order] [fragments][log [interval minutes] [threshold-in-msgs [ count]] [monitor]
To remove this filter, you have two choices:
  • Use the no seq sequence-number command if you know the filter’s sequence number.
  • Use the no permit tcp { source mask | any | host ip-address} { destination mask | any | host ip-address} command.
Parameters
source Enter the IP address of the network or host from which the packets were sent.
mask Enter a network mask in /prefix format (/x) or A.B.C.D. The mask, when specified in A.B.C.D format, may be either contiguous or non-contiguous.
any Enter the keyword any to specify that all routes are subject to the filter.
host ip-address Enter the keyword host then the IP address to specify a host IP address.
bit Enter a flag or combination of bits:
  • ack: acknowledgement field
  • fin: finish (no more data from the user)
  • psh: push function
  • rst: reset the connection
  • syn: synchronize sequence numbers
  • urg: urgent field
dscp Enter the keyword dscp to deny a packet based on the DSCP value. The range is from 0 to 63.
operator (OPTIONAL) Enter one of the following logical operand:
  • eq = equal to
  • neq = not equal to
  • gt = greater than
  • lt = less than
  • range = inclusive range of ports (you must specify two ports for the port parameter)
port port Enter the application layer port number. Enter two port numbers if you are using the range logical operand. The range is from 0 to 65535.
The following list includes some common TCP port numbers:
  • 23 = Telnet
  • 20 and 21 = FTP
  • 25 = SMTP
  • 169 = SNMP
destination Enter the IP address of the network or host to which the packets are sent.
mask Enter a network mask in /prefix format (/x) or A.B.C.D. The mask, when specified in A.B.C.D format, may be either contiguous or non-contiguous.
count (OPTIONAL) Enter the keyword count to count packets the filter processes.
byte (OPTIONAL) Enter the keyword byte to count bytes the filter processes.
order (OPTIONAL) Enter the keyword order to specify the QoS priority for the ACL entry. The range is from 0 to 254 (where 0 is the highest priority and 254 is the lowest; lower-order numbers have a higher priority). If you do not use the keyword order, the ACLs have the lowest order by default ( 255).
fragments Enter the keyword fragments to use ACLs to control packet fragments.
log (OPTIONAL) Enter the keyword log to enable the triggering of ACL log messages.
threshold-in msgs count (OPTIONAL) Enter the threshold-in-msgs keyword followed by a value to indicate the maximum number of ACL logs that can be generated, exceeding which the generation of ACL logs is terminated with the seq, permit, or deny commands. The threshold range is from 1 to 100.
interval minutes (OPTIONAL) Enter the keyword interval followed by the time period in minutes at which ACL logs must be generated. The threshold range is from 1 to 10 minutes.
monitor (OPTIONAL) Enter the keyword monitor when the rule is describing the traffic that you want to monitor and the ACL in which you are creating the rule is applied to the monitored interface.
Defaults

By default, 10 ACL logs are generated if you do not specify the threshold explicitly. The default frequency at which ACL logs are generated is five minutes. By default, flow-based monitoring is not enabled.

Command Modes CONFIGURATION-IP ACCESS-LIST-EXTENDED
Supported Modes Full–Switch
Command History
Version Description
9.9(0.0) Introduced on the FN IOM.
9.4(0.0) Added support for flow-based monitoring on the MXL 10/40GbE Switch IO Module platform.
9.3(0.0) Added support for logging of ACLs on the MXL 10/40GbE Switch IO Module platform.
8.3.16.1 Introduced on the MXL 10/40GbE Switch IO Module platform.
Usage Information

The order option is relevant in the context of the Policy QoS feature only. For more information, refer to the “Quality of Service” chapter of the Dell Networking OS Configuration Guide .

The switch cannot count both packets and bytes, so when you enter the count byte options, only bytes are incremented.

Most ACL rules require one entry in the CAM. However, rules with TCP and UDP port operators (for example, gt, lt, or range) may require more than one entry. The range of ports is configured in the CAM based on bit mask boundaries; the space required depends on exactly what ports are included in the range.

When the configured maximum threshold is exceeded, generation of logs is stopped. When the interval at which ACL logs are configured to be recorded expires, the subsequent, fresh interval timer is started and the packet count for that new interval commences from zero. If ACL logging was stopped previously because the configured threshold is exceeded, it is re-enabled for this new interval.

If ACL logging is stopped because the configured threshold is exceeded, it is re-enabled after the logging interval period elapses. ACL logging is supported for standard and extended IPv4 ACLs, IPv6 ACLs, and MAC ACLs. You can configure ACL logging only on ACLs that are applied to ingress interfaces; you cannot enable logging for ACLs that are associated with egress interfaces.

You can activate flow-based monitoring for a monitoring session by entering the flow-based enable command in the Monitor Session mode. When you enable this capability, traffic with particular flows that are traversing through the ingress and egress interfaces are examined and, appropriate ACLs can be applied in both the ingress and egress direction. Flow-based monitoring conserves bandwidth by monitoring only specified traffic instead all traffic on the interface. This feature is particularly useful when looking for malicious traffic. It is available for Layer 2 and Layer 3 ingress and egress traffic. You may specify traffic using standard or extended access-lists. This mechanism copies all incoming or outgoing packets on one port and forwards (mirrors) them to another port. The source port is the monitored port (MD) and the destination port is the monitoring port (MG).

Example

An ACL rule with a TCP port range of 4000–8000 uses eight entries in the CAM.

Dell# Data             Mask         From To   #Covered
                                             
                                             1 0000111110100000 1111111111100000 4000 4031 32
                                             2 0000111111000000 1111111111000000 4032 4095 64
                                             3 0001000000000000 1111100000000000 4096 6143 2048
                                             4 0001100000000000 1111110000000000 6144 7167 1024
                                             5 0001110000000000 1111111000000000 7168 7679 512
                                             6 0001111000000000 1111111100000000 7680 7935 256
                                             7 0001111100000000 1111111111000000 7936 7999 64
                                             8 0001111101000000 1111111111111111 8000 8000 1
                                             
                                             Total Ports: 4001
                                          
Example

An ACL rule with a TCP port lt 1023 uses only one entry in the CAM.

Dell# Data            Mask          From To   #Covered
                                             
                                             1 0000000000000000 1111110000000000 0    1023 1024
                                             
                                             Total Ports: 1024
                                          
Related Commands

ip access-list extended — creates an extended ACL.

permit — assigns a permit filter for IP packets.

permit udp — assigns a permit filter for UDP packets.


对此内容评级

准确性
有用性
易理解性
这篇文章对您有帮助吗?
0/3000 characters
  请提供评级(1-5星)。
  请提供评级(1-5星)。
  请提供评级(1-5星)。
  请选择这篇文章是否有帮助。
  注释中不得包含以下特殊字符:<>()\