linux; return “RTNETLINK responde: Operação não suportada” para criação de interface fictícia

Question

Estou tentando criar uma interface L3 no kernel v3.4.34, que não está conectada a uma interface / dispositivo físico e que deve ser usada apenas como uma interface de gerenciamento como uma interface visível externamente com o endereço IP.

Para isso, como root, tentei criar uma interface fictícia usando os comandos ip:

# ip link add test0 type dummy
RTNETLINK answers: Operation not supported

Se possível, alguém poderia comentar, como qualquer outra opção necessária para ativar as interfaces fictícias ou estou faltando alguma outra coisa?

A configuração atual é:

#
# Networking options
#
CONFIG_PACKET=y
CONFIG_UNIX=y
# CONFIG_UNIX_DIAG is not set
# CONFIG_NET_KEY is not set
CONFIG_INET=y
CONFIG_IP_MULTICAST=y
# CONFIG_IP_ADVANCED_ROUTER is not set
CONFIG_IP_ROUTE_CLASSID=y
CONFIG_IP_PNP=y
CONFIG_IP_PNP_DHCP=y
# CONFIG_IP_PNP_BOOTP is not set
# CONFIG_IP_PNP_RARP is not set
# CONFIG_NET_IPIP is not set
# CONFIG_NET_IPGRE_DEMUX is not set
# CONFIG_IP_MROUTE is not set
# CONFIG_ARPD is not set
CONFIG_SYN_COOKIES=y
# CONFIG_INET_AH is not set
# CONFIG_INET_ESP is not set
# CONFIG_INET_IPCOMP is not set
# CONFIG_INET_XFRM_TUNNEL is not set
# CONFIG_INET_TUNNEL is not set
# CONFIG_INET_XFRM_MODE_TRANSPORT is not set
# CONFIG_INET_XFRM_MODE_TUNNEL is not set
# CONFIG_INET_XFRM_MODE_BEET is not set
# CONFIG_INET_LRO is not set
CONFIG_INET_DIAG=y
CONFIG_INET_TCP_DIAG=y
# CONFIG_INET_UDP_DIAG is not set
# CONFIG_TCP_CONG_ADVANCED is not set
CONFIG_TCP_CONG_CUBIC=y
CONFIG_DEFAULT_TCP_CONG="cubic"
CONFIG_TCP_MD5SIG=y
CONFIG_IPV6=y
# CONFIG_IPV6_PRIVACY is not set
# CONFIG_IPV6_ROUTER_PREF is not set
# CONFIG_IPV6_OPTIMISTIC_DAD is not set
# CONFIG_INET6_AH is not set
# CONFIG_INET6_ESP is not set
# CONFIG_INET6_IPCOMP is not set
# CONFIG_IPV6_MIP6 is not set
# CONFIG_INET6_XFRM_TUNNEL is not set
# CONFIG_INET6_TUNNEL is not set
# CONFIG_INET6_XFRM_MODE_TRANSPORT is not set
# CONFIG_INET6_XFRM_MODE_TUNNEL is not set
# CONFIG_INET6_XFRM_MODE_BEET is not set
# CONFIG_INET6_XFRM_MODE_ROUTEOPTIMIZATION is not set
# CONFIG_IPV6_SIT is not set
# CONFIG_IPV6_TUNNEL is not set
# CONFIG_IPV6_MULTIPLE_TABLES is not set
# CONFIG_IPV6_MROUTE is not set
# CONFIG_NETWORK_SECMARK is not set
# CONFIG_NETWORK_PHY_TIMESTAMPING is not set
CONFIG_NETFILTER=y
# CONFIG_NETFILTER_DEBUG is not set
CONFIG_NETFILTER_ADVANCED=y
#
#
# Core Netfilter Configuration
#
CONFIG_NETFILTER_NETLINK=y
CONFIG_NETFILTER_NETLINK_ACCT=y
CONFIG_NETFILTER_NETLINK_QUEUE=y
CONFIG_NETFILTER_NETLINK_LOG=y
CONFIG_NF_CONNTRACK=y
CONFIG_NF_CONNTRACK_MARK=y
CONFIG_NF_CONNTRACK_ZONES=y
# CONFIG_NF_CONNTRACK_PROCFS is not set
CONFIG_NF_CONNTRACK_EVENTS=y
CONFIG_NF_CONNTRACK_TIMEOUT=y
CONFIG_NF_CONNTRACK_TIMESTAMP=y
# CONFIG_NF_CT_PROTO_DCCP is not set
# CONFIG_NF_CT_PROTO_SCTP is not set
# CONFIG_NF_CT_PROTO_UDPLITE is not set
# CONFIG_NF_CONNTRACK_AMANDA is not set
CONFIG_NF_CONNTRACK_FTP=y
# CONFIG_NF_CONNTRACK_H323 is not set
# CONFIG_NF_CONNTRACK_IRC is not set
CONFIG_NF_CONNTRACK_BROADCAST=y
# CONFIG_NF_CONNTRACK_NETBIOS_NS is not set
CONFIG_NF_CONNTRACK_SNMP=y
# CONFIG_NF_CONNTRACK_PPTP is not set
# CONFIG_NF_CONNTRACK_SANE is not set
# CONFIG_NF_CONNTRACK_SIP is not set
CONFIG_NF_CONNTRACK_TFTP=y
CONFIG_NF_CT_NETLINK=y
CONFIG_NF_CT_NETLINK_TIMEOUT=y
# CONFIG_NETFILTER_TPROXY is not set
CONFIG_NETFILTER_XTABLES=y

    

Answer 1

Você precisa ativar CONFIG_DUMMY :

config DUMMY
     tristate "Dummy net driver support"
     ---help---
       This is essentially a bit-bucket device (i.e. traffic you send to
       this device is consigned into oblivion) with a configurable IP
       address. It is most commonly used in order to make your currently
       inactive SLIP address seem like a real address for local programs.
       If you use SLIP or PPP, you might want to say Y here. Since this
       thing often comes in handy, the default is Y. It won't enlarge your
       kernel either. What a deal. Read about it in the Network
       Administrator's Guide, available from
       <http://www.tldp.org/docs.html#guide>.

       To compile this driver as a module, choose M here: the module
       will be called dummy.