Digisol DG-GS1550, Management Manual

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Configuring the Switch
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Access Control Lists
Access Control Lists (ACL) provide packet filtering for IP frames (based on address,
protocol, Layer 4 protocol port number or TCP control code) or any frames (based
on MAC address or Ethernet type). To filter incoming packets, first create an access
list, add the required rules, and then bind the list to a specific port.
Configuring Access Control Lists –
An ACL is a sequential list of permit or deny conditions that apply to IP addresses,
MAC addresses, or other more specific criteria. This switch tests ingress or egress
packets against the conditions in an ACL one by one. A packet will be accepted as
soon as it matches a permit rule, or dropped as soon as it matches a deny rule. If no
rules match for a list of all permit rules, the packet is dropped; and if no rules match
for a list of all deny rules, the packet is accepted.
Command Usage
The following restrictions apply to ACLs:
• Each ACL can have up to 32 rules.
• The maximum number of ACLs is also 32.
• The maximum number of rules that can be bound to the ports is 96 for each of the
following list types: MAC ACLs, IP ACLs (including Standard and Extended ACLs).
The order in which active ACLs are checked is as follows:
1. User-defined rules in IP and MAC ACLs for ingress ports are checked in parallel.
Rules within an ACL are checked in the configured order, from top to bottom.
If the result of checking an IP ACL is to permit a packet, but the result of a MAC
ACL on the same packet is to deny it, the packet will be denied (because the
decision to deny a packet has a higher priority for security reasons). A packet will
also be denied if the IP ACL denies it and the MAC ACL accepts it.
2. Explicit default rule (permit any any) in the ingress IP ACL for ingress ports.
3. If no explicit rule is matched, the implicit default is permit all.
Setting the ACL Name and Type
Use the ACL Configuration page to designate the name and type of an ACL.
Command Attributes
• Name – Name of the ACL. (Maximum length: 15 characters)
• Type – There are three filtering modes:
- Standard – IP ACL mode that filters packets based on the source IP address.
- Extended – IP ACL mode that filters packets based on source or destination IP
address, as well as protocol type and protocol port number.
- MAC – MAC ACL mode that filters packets based on the source or destination
MAC address and the Ethernet frame type (RFC 1060).