Pergunta engraçada. Parece que você pode ver valores snmp de um processo em /proc/[pid]/net/dev_snmp6/[DEV] pelo menos para IP6:
ifIndex 4
Ip6InReceives 4
Ip6InHdrErrors 0
Ip6InTooBigErrors 0
Ip6InNoRoutes 0
Ip6InAddrErrors 0
Ip6InUnknownProtos 0
Ip6InTruncatedPkts 0
Ip6InDiscards 0
Ip6InDelivers 4
Ip6OutForwDatagrams 0
Ip6OutRequests 24
Ip6OutDiscards 0
Ip6OutNoRoutes 0
Ip6ReasmTimeout 0
Ip6ReasmReqds 0
Ip6ReasmOKs 0
Ip6ReasmFails 0
Ip6FragOKs 0
Ip6FragFails 0
Ip6FragCreates 0
Ip6InMcastPkts 2
Ip6OutMcastPkts 34
Ip6InOctets 618
Ip6OutOctets 1946
Ip6InMcastOctets 304
Ip6OutMcastOctets 2786
Ip6InBcastOctets 0
Ip6OutBcastOctets 0
Ip6InNoECTPkts 4
Ip6InECT1Pkts 0
Ip6InECT0Pkts 0
Ip6InCEPkts 0
Icmp6InMsgs 2
Icmp6InErrors 0
Icmp6OutMsgs 22
Icmp6OutErrors 0
Icmp6InCsumErrors 0
Icmp6InDestUnreachs 0
Icmp6InPktTooBigs 0
Icmp6InTimeExcds 0
Icmp6InParmProblems 0
Icmp6InEchos 0
Icmp6InEchoReplies 0
Icmp6InGroupMembQueries 0
Icmp6InGroupMembResponses 0
Icmp6InGroupMembReductions 0
Icmp6InRouterSolicits 0
Icmp6InRouterAdvertisements 2
Icmp6InNeighborSolicits 0
Icmp6InNeighborAdvertisements 0
Icmp6InRedirects 0
Icmp6InMLDv2Reports 0
Icmp6OutDestUnreachs 0
Icmp6OutPktTooBigs 0
Icmp6OutTimeExcds 0
Icmp6OutParmProblems 0
Icmp6OutEchos 0
Icmp6OutEchoReplies 0
Icmp6OutGroupMembQueries 0
Icmp6OutGroupMembResponses 0
Icmp6OutGroupMembReductions 0
Icmp6OutRouterSolicits 9
Icmp6OutRouterAdvertisements 0
Icmp6OutNeighborSolicits 3
Icmp6OutNeighborAdvertisements 0
Icmp6OutRedirects 0
Icmp6OutMLDv2Reports 10
Icmp6InType134 2
Icmp6OutType133 9
Icmp6OutType135 3
Icmp6OutType143 10
mas é bem provável que seja um recurso especial do kernel no qual eu finalmente compilei.