This Confluence has been LDAP enabled, if you are an ASF Committer, please use your LDAP Credentials to login. Any problems file an INFRA jira ticket please.

Page tree
Skip to end of metadata
Go to start of metadata

DCC (from

DCC (Distributed Checksum Clearinghouse) is a system similar to Razor. It supports fuzzy checksums and therefore detects some more spams than Razor does at the moment.

To install it, perform the following steps:

	tar xfvz dcc.tar.Z
	cd dcc-2.3.167
	CFLAGS="-O2 -fstack-protector" DCC_CFLAGS="-O2 -fstack-protector" ./configure && make && make install

You might want to replace the configure call with something like this to get an FHS compliant install:

	./configure \
		--bindir=$(PREFIX)/bin \
		--libexecdir=$(PREFIX)/lib/dcc \
		--mandir=$(PREFIX)/man \

It's recommended to run the persistent dccifd daemon for sites scanning more messages.

This method assumes you are not using DCC / dccifd for anything else than scanning with SA. If you are using any other features like DCC server, greylisting etc, see:

	# create dcc user to run dccifd safely (Linux specific useradd arguments)
	useradd -m -U -d /var/dcc -s /bin/sh dcc 
	# homedir needs to be owned by the user
	chown -hR dcc:dcc /var/dcc
	# start dccifd as dcc user (you could add this to /etc/rc.local for system startup, or see your OS manual)
	su - -c '/var/dcc/libexec/dccifd' dcc

Finally call cdcc:

        cdcc info

The last command will give some output. The output should contain lines like this:,-         RTT+0 ms    anon,-         RTT+0 ms    anon

There should be *at least one*, preferably more than half a dozen, of the public DCC servers listed. If this is not the case, a likely cause is an interfering firewall (see UsingDcc).

More info is at UsingDcc.

  • No labels