To use knetfilter your kernel should be compiled with FULL netfilter support enabled.
Here is the configuration I do suggest based on Linux kernel 2.6.9. (Please, note that I DO USE arpd)
# Networking options
#
CONFIG_PACKET=y
CONFIG_PACKET_MMAP=y
CONFIG_NETLINK=y
CONFIG_RTNETLINK=y
CONFIG_NETLINK_DEV=y
CONFIG_NETFILTER=y
# CONFIG_NETFILTER_DEBUG is not set
CONFIG_FILTER=y
CONFIG_UNIX=y
CONFIG_INET=y
CONFIG_IP_MULTICAST=y
CONFIG_IP_ADVANCED_ROUTER=y
CONFIG_RTNETLINK=y
CONFIG_NETLINK=y
CONFIG_IP_MULTIPLE_TABLES=y
CONFIG_IP_ROUTE_FWMARK=y
CONFIG_IP_ROUTE_NAT=y
CONFIG_IP_ROUTE_MULTIPATH=y
CONFIG_IP_ROUTE_TOS=y
CONFIG_IP_ROUTE_VERBOSE=y
CONFIG_IP_ROUTE_LARGE_TABLES=y
# CONFIG_IP_PNP is not set
# CONFIG_NET_IPIP is not set
# CONFIG_NET_IPGRE is not set
# CONFIG_IP_MROUTE is not set
CONFIG_ARPD=y
CONFIG_INET_ECN=y
CONFIG_SYN_COOKIES=y
# CONFIG_INET_AH is not set
# CONFIG_INET_ESP is not set
# CONFIG_INET_IPCOMP is not set
# IP: Virtual Server Configuration
#
# CONFIG_IP_VS is not set
# CONFIG_IPV6 is not set
CONFIG_NETFILTER=y
# CONFIG_NETFILTER_DEBUG is not set
#
# IP: Netfilter Configuration
#
CONFIG_IP_NF_CONNTRACK=m
CONFIG_IP_NF_FTP=m
CONFIG_IP_NF_IRC=m
CONFIG_IP_NF_TFTP=m
CONFIG_IP_NF_AMANDA=m
CONFIG_IP_NF_QUEUE=m
CONFIG_IP_NF_IPTABLES=m
CONFIG_IP_NF_MATCH_LIMIT=m
CONFIG_IP_NF_MATCH_IPRANGE=m
CONFIG_IP_NF_MATCH_MAC=m
CONFIG_IP_NF_MATCH_PKTTYPE=m
CONFIG_IP_NF_MATCH_MARK=m
CONFIG_IP_NF_MATCH_MULTIPORT=m
CONFIG_IP_NF_MATCH_TOS=m
CONFIG_IP_NF_MATCH_RECENT=m
CONFIG_IP_NF_MATCH_ECN=m
CONFIG_IP_NF_MATCH_DSCP=m
CONFIG_IP_NF_MATCH_AH_ESP=m
CONFIG_IP_NF_MATCH_LENGTH=m
CONFIG_IP_NF_MATCH_TTL=m
CONFIG_IP_NF_MATCH_TCPMSS=m
CONFIG_IP_NF_MATCH_HELPER=m
CONFIG_IP_NF_MATCH_STATE=m
CONFIG_IP_NF_MATCH_CONNTRACK=m
CONFIG_IP_NF_MATCH_OWNER=m
CONFIG_IP_NF_FILTER=m
CONFIG_IP_NF_TARGET_REJECT=m
CONFIG_IP_NF_NAT=m
CONFIG_IP_NF_NAT_NEEDED=y
CONFIG_IP_NF_TARGET_MASQUERADE=m
CONFIG_IP_NF_TARGET_REDIRECT=m
CONFIG_IP_NF_TARGET_NETMAP=m
CONFIG_IP_NF_TARGET_SAME=m
CONFIG_IP_NF_NAT_LOCAL=y
CONFIG_IP_NF_NAT_SNMP_BASIC=m
CONFIG_IP_NF_NAT_IRC=m
CONFIG_IP_NF_NAT_FTP=m
CONFIG_IP_NF_NAT_TFTP=m
CONFIG_IP_NF_NAT_AMANDA=m
CONFIG_IP_NF_MANGLE=m
CONFIG_IP_NF_TARGET_TOS=m
CONFIG_IP_NF_TARGET_ECN=m
CONFIG_IP_NF_TARGET_DSCP=m
CONFIG_IP_NF_TARGET_MARK=m
CONFIG_IP_NF_TARGET_CLASSIFY=m
CONFIG_IP_NF_TARGET_LOG=m
CONFIG_IP_NF_TARGET_ULOG=m
CONFIG_IP_NF_TARGET_TCPMSS=m
CONFIG_IP_NF_ARPTABLES=m
CONFIG_IP_NF_ARPFILTER=m
CONFIG_IP_NF_ARP_MANGLE=m
# CONFIG_IP_NF_COMPAT_IPCHAINS is not set
# CONFIG_IP_NF_COMPAT_IPFWADM is not set
CONFIG_IP_NF_TARGET_NOTRACK=m
CONFIG_IP_NF_RAW=m
CONFIG_IP_NF_MATCH_ADDRTYPE=m
CONFIG_IP_NF_MATCH_REALM=m
Knetfilter is also able to act at QoS GUI for firewall packet classifier based QoS.
In order to do so, you need to have iptools2 installed, and your kernel should be configured as follow:
#
# QoS and/or fair queueing
#
CONFIG_NET_SCHED=y
# CONFIG_NET_SCH_CLK_JIFFIES is not set
# CONFIG_NET_SCH_CLK_GETTIMEOFDAY is not set
CONFIG_NET_SCH_CLK_CPU=y
CONFIG_NET_SCH_CBQ=m
CONFIG_NET_SCH_HTB=m
CONFIG_NET_SCH_HFSC=m
CONFIG_NET_SCH_PRIO=m
CONFIG_NET_SCH_RED=m
CONFIG_NET_SCH_SFQ=m
CONFIG_NET_SCH_TEQL=m
CONFIG_NET_SCH_TBF=m
CONFIG_NET_SCH_GRED=m
CONFIG_NET_SCH_DSMARK=m
CONFIG_NET_SCH_NETEM=m
CONFIG_NET_SCH_INGRESS=m
CONFIG_NET_QOS=y
CONFIG_NET_ESTIMATOR=y
CONFIG_NET_CLS=y
CONFIG_NET_CLS_TCINDEX=m
CONFIG_NET_CLS_ROUTE4=m
CONFIG_NET_CLS_ROUTE=y
CONFIG_NET_CLS_FW=y
CONFIG_NET_CLS_U32=m
CONFIG_CLS_U32_PERF=y
# CONFIG_NET_CLS_IND is not set
CONFIG_NET_CLS_RSVP=m
# CONFIG_NET_CLS_RSVP6 is not set
CONFIG_NET_CLS_ACT=y
CONFIG_NET_ACT_POLICE=y
If you prefer (as you should) to use netfilter modules, please load them all.
If you want, you can use this script.
#!/bin/sh
modprobe ip_conntrack
modprobe ip_conntrack_ftp
modprobe ip_conntrack_amanda
modprobe ip_conntrack_irc
modprobe ip_conntrack_tftp
modprobe ip_nat_ftp
modprobe ip_nat_amanda
modprobe ip_nat_irc
modprobe ip_nat_tftp
modprobe ip_nat_snmp_basic
modprobe ip_queue
modprobe ip_tables
modprobe ipt_DSCP
modprobe ipt_ECN
modprobe ipt_LOG
modprobe ipt_ULOG
modprobe ipt_MARK
modprobe ipt_MASQUERADE
modprobe ipt_MIRROR
modprobe ipt_REDIRECT
modprobe ipt_SAME
modprobe ipt_REJECT
modprobe ipt_TOS
modprobe ipt_TCPMSS
modprobe ipt_CLASSIFY
modprobe ipt_NETMAP
modprobe ipt_SAME
modprobe ipt_limit
modprobe ipt_ah
modprobe ipt_conntrack
modprobe ipt_dscp
modprobe ipt_ecn
modprobe ipt_esp
modprobe ipt_helper
modprobe ipt_iprange
modprobe ipt_length
modprobe ipt_mac
modprobe ipt_mark
modprobe ipt_multiport
modprobe ipt_owner
modprobe ipt_recent
modprobe ipt_pkttype
modprobe ipt_state
modprobe ipt_tos
modprobe ipt_unclean
modprobe ipt_tcpmss
modprobe ipt_ttl
modprobe iptable_filter
modprobe iptable_mangle
modprobe iptable_nat
modprobe arp_table
modprobe arpt_mangle
modprobe arptable_filter
About QoS modules, be carefull, and load what you need, anyway you need to read a lot of documentation about how different schedulers work.
Buon Divertimento!