Configuring Admission Rules

Configuring Admission Rules

Once NAT has been auspiciously configured as apparent in the antecedent exercise,

internal audience should be able to admission alien resources. Even admitting a specific

rule has not been manually added to acquiesce such outbound access, it is implied

through the configured interface aegis levels.

Using Cisco parlance, cartage is consistently acceptable from firewall interfaces with

higher aegis levels to interfaces with lower aegis levels. For instance, in the

example arrangement architecture, the alien interface of the firewall at address

192.168.1.2 has a aegis akin of 0, and the centralized interface of the firewall

at abode 172.20.1.1 has a aegis akin of 100.This allows centralized cartage to

traverse the firewall outbound after especially allowing it.

However, this adumbrated aphorism is antipodal for cartage traversing from a lower

security-level interface to a college aegis level. Such cartage advancing from outside

networks to central networks is consistently around denied unless permitted.

Therefore, you charge add an admission aphorism to admittance any entering traffic.

To add admission rules, bang the Admission Rules tab from the PDM main

window.The Admission Rules tab awning appears, as apparent in Figure 9.56.

www.syngress.com

Figure 9.56 The Admission Rules Screen

PIX Device Manager • Chapter 9 513

Note the absolute aphorism automatically added by the PIX firewall around permitting

outbound admission through the firewall. From this screen, you can configure

access rules,AAA rules, and clarify rules appliance the Admission Rules, AAA Rules, and

Filter Rules radio buttons, respectively. Admission rules are acclimated to admittance and deny

specific cartage through the firewall.AAA rules are acclimated to configure AAA on specific

connections acceptable through the firewall. Finally, clarify rules are acclimated to

permit or abjure specific URLs or appliance functionality such as Java or

ActiveX outbound. As with adaptation rules, you can dispense all these rules

via the PDM capital card drop-down menus, via the adjustment buttons, or by

right-clicking your abrasion in the rules screen.