---
name: "bihourly"
section: "8"
platform: "linux"
package: "arpwatch"
version: "2.1a15-9"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/bihourly"
---

# bihourly(8)

track ethernet/ip address pairs

## NAME

bihourly - track ethernet/ip address pairs

## SYNOPSIS

bihourly

## DESCRIPTION

**bihourly** is a script that automates the operation of **[arpsnmp(8)](/arpsnmp/8.md)** by executing **[arpfetch(8)](/arpfetch/8.md)** on a series of hostnames and then sending the results to **[arpsnmp(8)](/arpsnmp/8.md)** for analysis.

The result is a report of the current pairings between ip addresses and the corresponding ethernet address of the network hardware as reported by **snmpwalk(8).** Activity is logged and noted changes are reported by email.

In its working directory **bihourly** expects a file named *list* which contains a space separated list of hostnames to be queried and a file named *cname* which holds the SNMP community name by which to query these hosts.

Contrary to the name, **bihourly** does not run twice every hour. It runs once each time it is invoked. For repeated operation **bihourly** must be invoked on a periodic basis by a program like **cron(1).**

## FILES

```
/var/lib/arpwatch - default working directory
list - file containing names of hosts to query
cname - file containing the SNMP community name by which to query
```

## SEE ALSO

[**arpsnmp**(8)](/arpsnmp/8.md), **[arpfetch(8)](/arpfetch/8.md),** **snmpwalk**(8), [**cron**(8)](/cron/8.md)

## BUGS

Please send bug reports to arpwatch@ee.lbl.gov.

## AUTHORS

Craig Leres of the Lawrence Berkeley National Laboratory Network Research Group, University of California, Berkeley, CA.

The current version is available via anonymous ftp:

*ftp://ftp.ee.lbl.gov/arpwatch.tar.gz*

This manual page was contributed by Hugo Graumann.