All Cisco-Network Study Notes

The appearance conn Command

Each affiliation fabricated to the firewall additionally consumes memory.The bulk of

memory captivated depends on the blazon of connection. A UDP connection

consumes 120 bytes; a TCP affiliation requires 200 bytes.This anamnesis consumption

is all-important to body the affiliation and advance accompaniment information.

Here is an archetype of the appearance conn command:

PIX1# sh conn

2 in use, 2 best used

If we accept 100 TCP access fabricated through this PIX firewall, that will

require 20K of capital memory. Of course, this is a concise cardinal and will

fluctuate depending on the times of the day

The appearance xlate Command

One action that consumes anamnesis is abode translation. Each translation

requires about 56 bytes of memory. Knowing this, you can run the show

xlate command. For example:

PIX1# appearance xlate

100 in use, 341 best used

Multiply the cardinal of translations by 56 bytes to actuate how much

memory has been captivated for translations. In our example, we accept 100

translations in use, which agency we accept 5600 bytes of anamnesis allocated

for adaptation alone.

The appearance anamnesis Command

The appearance anamnesis command provides an calmly apprehensible overview of how

much anamnesis is installed and how abundant is currently actuality used.This command

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610 Chapter 10 • Troubleshooting and Performance Monitoring

simply shows you the bulk of absolute and chargeless anamnesis at the time that you run

the command. Here is an archetype of the appearance anamnesis command:

PIX1# appearance memory

16777216 bytes total, 4517888 bytes free

To optimize the account of this command, run it on a PIX firewall that has

a actual basal configuration.That is, run it on a PIX firewall that is not running

encryption or added functions and almanac that information.Then as you add

features, assassinate the command and analyze the output. Doing so enables you

to almanac about how abundant anamnesis is captivated by anniversary process.

Memory Achievement Monitoring

Memory appliance can be as important in free achievement as the

CPU. Beam anamnesis is acclimated to authority the PIX operating arrangement and configuration.

Unless you accept a actual ample software image, allocation issues with beam memory

are not a concern. Capital memory, the focus of this section, is the alive space

of the PIX firewall.When the PIX firewall aboriginal boots, it initializes and runs the

OS from beam memory. It does not bulk the OS into capital memory, which is

used for abstracts only.The anamnesis is additionally acclimated for all processes as able-bodied as buffering

incoming and approachable traffic. Because it is acclimated by so abounding altered aspects of

the firewall, it is analytical to ensure that you accept abundant memory.You can run

several commands to advice with this task. In addition, agnate to CPU utilization,

we acclaim application an SNMP apparatus such as MRTG or HP OpenView to monitor

the bulk of accessible anamnesis on the PIX firewall.

The appearance perfmon Command

One acutely advantageous command for achievement ecology on the PIX firewall

is the appearance perfmon command. It shows capacity a cardinal of statistics, including

translations, connections, fixup, and AAA.This is the alone command that you can

use to appearance the “average” ethics for the cardinal of translations and connections

on the firewall.The nice affair about this command is that it break the connections

down by protocol, as apparent in the achievement in Figure 10.26.This breakdown

can advice you actuate if a accurate affiliation is application up too abundant CPU or

memory.Table 10.6 lists the ethics in the appearance perfmon command.

Figure 10.26 Achievement of the appearance perfmon Command

PIX1# appearance perfmon

PERFMON STATS: Current Average

Xlates 0/s 0/s

Connections 0/s 0/s

TCP Conns 0/s 0/s

UDP Conns 0/s 0/s

URL Access 0/s 0/s

URL Server Req 0/s 0/s

TCP Fixup 0/s 0/s

TCPIntercept 0/s 0/s

HTTP Fixup 0/s 0/s

FTP Fixup 0/s 0/s

AAA Authen 0/s 0/s

AAA Author 0/s 0/s

AAA Account 0/s 0/s

Table 10.6 Ethics in the appearance perfmon Command

Parameter Description

Xlates Translations congenital up per second.

Connections Access accustomed per second.

TCP Conns TCP access per second.

UDP Conns UDP access per second.

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Troubleshooting and Achievement Ecology • Chapter 10 609

Parameter Description

URL Access URLs (Web sites) accessed per second.

URL Server Req Requests beatific to Websense/N2H2 per additional (requires the

filter command).

TCP Fixup Cardinal of TCP packets that the PIX forwarded per second.

TCP Intercept Cardinal of SYN packets per additional that accept exceeded the

configured beginning limit.

HTTP Fixup Cardinal of packets destined to anchorage 80 per additional (requires

the fixup agreement http command).

FTP Fixup FTP commands inspected per second.

AAA Authen Authentication requests per second.

AAA Author Authorization requests per second.

AAA Account Accounting requests per second.

As with any measurement, if you do not accept a baseline, this blazon of information

is useless. Execute the command on a approved base over time to body a baseline.

You can again analyze ethics to this baseline to acquisition anomalies.