Октябрь | 2016

На Linux машине подключены 2 ISP, один из них:
eth2: 189.1.1.31/25, GW: 189.1.1.1

Настроены rules:

ip rule add from 189.1.1.31 table ISP2
ip route add default via 189.1.1.1 table ISP2

1 2	ip rule add from 189.1.1.31 table ISP2 ip route add default via 189.1.1.1 table ISP2

Попробуем отправить трафик через ISP2:

linux# ping -I eth2  -c 1 77.88.8.8
PING 77.88.8.8 (77.88.8.8) from 189.1.1.31 eth2: 56(84) bytes of data.
64 bytes from 77.88.8.8: icmp_seq=1 ttl=60 time=1.10 ms
^C
--- 77.88.8.8 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 1.101/1.101/1.101/0.000 ms

linux# ping -I eth2 -c 1 77.88.8.8

PING 77.88.8.8 (77.88.8.8) from 189.1.1.31 eth2: 56(84) bytes of data.

64 bytes from 77.88.8.8: icmp_seq=1 ttl=60 time=1.10 ms

--- 77.88.8.8 ping statistics ---

1 packets transmitted, 1 received, 0% packet loss, time 0ms

rtt min/avg/max/mdev = 1.101/1.101/1.101/0.000 ms

В этот момент на интерфейсе:

linux# tcpdump -vvnpi eth2 "(arp or icmp) and (src or dst 189.1.1.31)"
tcpdump: listening on eth2, link-type EN10MB (Ethernet), capture size 262144 bytes
13:09:12.672150 ARP, Ethernet (len 6), IPv4 (len 4), Request who-has 77.88.8.8 tell 189.1.1.31, length 28
13:09:12.672619 ARP, Ethernet (len 6), IPv4 (len 4), Reply 77.88.8.8 is-at 00:07:0e:5c:d5:a2, length 46
13:09:12.672630 IP (tos 0x0, ttl 64, id 57740, offset 0, flags [DF], proto ICMP (1), length 84)
    189.1.1.31 > 77.88.8.8: ICMP echo request, id 2757, seq 1, length 64
13:09:12.673186 IP (tos 0x0, ttl 60, id 23933, offset 0, flags [none], proto ICMP (1), length 84)
    77.88.8.8 > 189.1.1.31: ICMP echo reply, id 2757, seq 1, length 64
^C

linux# tcpdump -vvnpi eth2 "(arp or icmp) and (src or dst 189.1.1.31)"

tcpdump: listening on eth2, link-type EN10MB (Ethernet), capture size 262144 bytes

13:09:12.672150 ARP, Ethernet (len 6), IPv4 (len 4), Request who-has 77.88.8.8 tell 189.1.1.31, length 28

13:09:12.672619 ARP, Ethernet (len 6), IPv4 (len 4), Reply 77.88.8.8 is-at 00:07:0e:5c:d5:a2, length 46

13:09:12.672630 IP (tos 0x0, ttl 64, id 57740, offset 0, flags [DF], proto ICMP (1), length 84)

189.1.1.31 > 77.88.8.8: ICMP echo request, id 2757, seq 1, length 64

13:09:12.673186 IP (tos 0x0, ttl 60, id 23933, offset 0, flags [none], proto ICMP (1), length 84)

77.88.8.8 > 189.1.1.31: ICMP echo reply, id 2757, seq 1, length 64

Появилась ARP запись:

linux# arp -n 77.88.8.8
Address        HWtype  HWaddress           Flags Mask    Iface
77.88.8.8      ether   00:07:0e:5c:d5:a2   C             eth2

linux# arp -n 77.88.8.8

Address HWtype HWaddress Flags Mask Iface

77.88.8.8 ether 00:07:0e:5c:d5:a2 C eth2

Хорошо что у ISP роутер Cisco на которой включен Proxy-ARP по умолчанию:

linux# arp -n 189.1.1.1
? (189.1.1.1) at 00:07:0e:5c:d5:a2 [ether] on eth2

1 2	linux# arp -n 189.1.1.1 ? (189.1.1.1) at 00:07:0e:5c:d5:a2 [ether] on eth2

Иначе бы ответа не последовало.

Решение:

ip rule add oif eth2 table ISP2

1	ip rule add oif eth2 table ISP2

Проверяем

linux# ping -I eth2 -c 1 77.88.8.88
PING 77.88.8.88 (77.88.8.88) from 189.1.1.31 eth2: 56(84) bytes of data.
64 bytes from 77.88.8.88: icmp_seq=1 ttl=60 time=12.5 ms
--- 77.88.8.88 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 12.591/12.591/12.591/0.000 ms

linux# ping -I eth2 -c 1 77.88.8.88

PING 77.88.8.88 (77.88.8.88) from 189.1.1.31 eth2: 56(84) bytes of data.

64 bytes from 77.88.8.88: icmp_seq=1 ttl=60 time=12.5 ms

--- 77.88.8.88 ping statistics ---

1 packets transmitted, 1 received, 0% packet loss, time 0ms

rtt min/avg/max/mdev = 12.591/12.591/12.591/0.000 ms

linux# tcpdump -evvnpi eth2 "(arp or icmp) and (src or dst 189.1.1.31)"
tcpdump: listening on eth2, link-type EN10MB (Ethernet), capture size 262144 bytes
13:17:38.916995 00:15:58:6d:c3:56 > 00:07:0e:5c:d5:a2, ethertype IPv4 (0x0800), length 98: (tos 0x0, ttl 64, id 44729, offset 0, flags [DF], proto ICMP (1), length 84)
    189.1.1.31 > 77.88.8.88: ICMP echo request, id 2786, seq 1, length 64
13:17:38.929527 00:07:0e:5c:d5:a2 > 00:15:58:6d:c3:56, ethertype IPv4 (0x0800), length 98: (tos 0x0, ttl 60, id 2576, offset 0, flags [none], proto ICMP (1), length 84)
    77.88.8.88 > 189.1.1.31: ICMP echo reply, id 2786, seq 1, length 64
^C

linux# tcpdump -evvnpi eth2 "(arp or icmp) and (src or dst 189.1.1.31)"

tcpdump: listening on eth2, link-type EN10MB (Ethernet), capture size 262144 bytes

13:17:38.916995 00:15:58:6d:c3:56 > 00:07:0e:5c:d5:a2, ethertype IPv4 (0x0800), length 98: (tos 0x0, ttl 64, id 44729, offset 0, flags [DF], proto ICMP (1), length 84)

189.1.1.31 > 77.88.8.88: ICMP echo request, id 2786, seq 1, length 64

13:17:38.929527 00:07:0e:5c:d5:a2 > 00:15:58:6d:c3:56, ethertype IPv4 (0x0800), length 98: (tos 0x0, ttl 60, id 2576, offset 0, flags [none], proto ICMP (1), length 84)

77.88.8.88 > 189.1.1.31: ICMP echo reply, id 2786, seq 1, length 64

linux# arp -n 77.88.8.88
77.88.8.88 (77.88.8.88) -- no entry

1 2	linux# arp -n 77.88.8.88 77.88.8.88 (77.88.8.88) -- no entry

Изначально кто-то/когда-то назначает IP на интерфейс xl0, примерно так:

fbsd# ifconfig xl0 alias 10.10.1.251/24 up
fbsd# ifconfig xl0
xl0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
        options=82009<RXCSUM,VLAN_MTU,WOL_MAGIC,LINKSTATE>
        ether 00:04:75:70:ab:06
        inet 10.55.5.51 netmask 0xffffff00 broadcast 10.55.5.255
        inet 10.10.1.251 netmask 0xffffff00 broadcast 10.10.1.255
        media: Ethernet autoselect (100baseTX <full-duplex>)
        status: active

fbsd# ifconfig xl0 alias 10.10.1.251/24 up

fbsd# ifconfig xl0

xl0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500

options=82009<RXCSUM,VLAN_MTU,WOL_MAGIC,LINKSTATE>

ether 00:04:75:70:ab:06

inet 10.55.5.51 netmask 0xffffff00 broadcast 10.55.5.255

inet 10.10.1.251 netmask 0xffffff00 broadcast 10.10.1.255

media: Ethernet autoselect (100baseTX <full-duplex>)

status: active

Далее возникает задача подключить сеть 10.10.1.0/24 в VLAN18 на интерфейсе xl0, но мы изначально не знаем что у нас висит данная сеть на xl0 нативно.

Вешаем:

fbsd# ifconfig vlan18 10.10.1.251/24 up

1	fbsd# ifconfig vlan18 10.10.1.251/24 up

Пробуем пропинговать адрес шлюза с удаленной машины в VLAN18:

hostA# ping -c 3 10.10.1.251
PING 10.10.1.251 (10.10.1.251) 56(84) bytes of data.
--- 10.10.1.251 ping statistics ---
3 packets transmitted, 0 received, 100% packet loss, time 2001ms

hostA# ping -c 3 10.10.1.251

PING 10.10.1.251 (10.10.1.251) 56(84) bytes of data.

--- 10.10.1.251 ping statistics ---

3 packets transmitted, 0 received, 100% packet loss, time 2001ms

Ответа нет, но ARP добавился:

hostA# arp -n 10.10.1.251
Address HWtype HWaddress Flags Mask Iface
10.10.1.251 ether 00:04:75:70:ab:06 C eth0

hostA# arp -n 10.10.1.251

Address HWtype HWaddress Flags Mask Iface

10.10.1.251 ether 00:04:75:70:ab:06 C eth0

Со стороны сервера:

fbsd# arp -an | grep vlan18
? (10.10.1.21) at 00:0d:61:b0:8a:b1 on vlan18 expires in 1088 seconds [vlan]

1 2	fbsd# arp -an \| grep vlan18 ? (10.10.1.21) at 00:0d:61:b0:8a:b1 on vlan18 expires in 1088 seconds [vlan]

Здесь нужно было смотреть так (и сразу было бы все понятно):

fbsd# arp -an | grep 10.10.1.
? (10.10.1.21) at 00:0d:61:b0:8a:b1 on vlan18 expires in 1088 seconds [vlan]
? (10.10.1.251) at 00:04:75:70:ab:06 on xl0 permanent [ethernet]

fbsd# arp -an | grep 10.10.1.

? (10.10.1.21) at 00:0d:61:b0:8a:b1 on vlan18 expires in 1088 seconds [vlan]

? (10.10.1.251) at 00:04:75:70:ab:06 on xl0 permanent [ethernet]

Посмотрим на трафик в VLAN18:

fbsd# tcpdump -evvnpi vlan18 host 10.10.1.21
tcpdump: listening on vlan18, link-type EN10MB (Ethernet), capture size 65535 bytes
02:20:20.606963 00:0d:61:b0:8a:b1 > ff:ff:ff:ff:ff:ff, ethertype ARP (0x0806), length 60: Ethernet (len 6), IPv4 (len 4), Request who-has 10.10.1.251 tell 10.10.1.21, length 46
02:20:20.606977 00:04:75:70:ab:06 > 00:0d:61:b0:8a:b1, ethertype ARP (0x0806), length 42: Ethernet (len 6), IPv4 (len 4), Reply 10.10.1.251 is-at 00:04:75:70:ab:06, length 28
02:20:20.608051 00:0d:61:b0:8a:b1 > 00:04:75:70:ab:06, ethertype IPv4 (0x0800), length 74: (tos 0x0, ttl 128, id 24924, offset 0, flags [none], proto ICMP (1), length 60)
10.10.1.21 > 10.10.1.251: ICMP echo request, id 512, seq 33280, length 40
02:20:25.717835 00:0d:61:b0:8a:b1 > 00:04:75:70:ab:06, ethertype IPv4 (0x0800), length 74: (tos 0x0, ttl 128, id 26156, offset 0, flags [none], proto ICMP (1), length 60)
10.10.1.21 > 10.10.1.251: ICMP echo request, id 512, seq 33536, length 40
02:20:31.295146 00:0d:61:b0:8a:b1 > 00:04:75:70:ab:06, ethertype IPv4 (0x0800), length 74: (tos 0x0, ttl 128, id 27110, offset 0, flags [none], proto ICMP (1), length 60)
10.10.1.21 > 10.10.1.251: ICMP echo request, id 512, seq 33792, length 40
^C
5 packets captured

fbsd# tcpdump -evvnpi vlan18 host 10.10.1.21

tcpdump: listening on vlan18, link-type EN10MB (Ethernet), capture size 65535 bytes

02:20:20.606963 00:0d:61:b0:8a:b1 > ff:ff:ff:ff:ff:ff, ethertype ARP (0x0806), length 60: Ethernet (len 6), IPv4 (len 4), Request who-has 10.10.1.251 tell 10.10.1.21, length 46

02:20:20.606977 00:04:75:70:ab:06 > 00:0d:61:b0:8a:b1, ethertype ARP (0x0806), length 42: Ethernet (len 6), IPv4 (len 4), Reply 10.10.1.251 is-at 00:04:75:70:ab:06, length 28

02:20:20.608051 00:0d:61:b0:8a:b1 > 00:04:75:70:ab:06, ethertype IPv4 (0x0800), length 74: (tos 0x0, ttl 128, id 24924, offset 0, flags [none], proto ICMP (1), length 60)

10.10.1.21 > 10.10.1.251: ICMP echo request, id 512, seq 33280, length 40

02:20:25.717835 00:0d:61:b0:8a:b1 > 00:04:75:70:ab:06, ethertype IPv4 (0x0800), length 74: (tos 0x0, ttl 128, id 26156, offset 0, flags [none], proto ICMP (1), length 60)

10.10.1.21 > 10.10.1.251: ICMP echo request, id 512, seq 33536, length 40

02:20:31.295146 00:0d:61:b0:8a:b1 > 00:04:75:70:ab:06, ethertype IPv4 (0x0800), length 74: (tos 0x0, ttl 128, id 27110, offset 0, flags [none], proto ICMP (1), length 60)

10.10.1.21 > 10.10.1.251: ICMP echo request, id 512, seq 33792, length 40

5 packets captured

ARP Req приходит в VLAN18 (куда ему деваться), ARP Res также через VLAN18.

Одноврменно с этим посмотрим что происходит на интерфейсе xl0:

fbsd# tcpdump -evvnpi xl0 host 10.10.1.21
tcpdump: listening on xl0, link-type EN10MB (Ethernet), capture size 65535 bytes
02:20:20.608069 00:04:75:70:ab:06 > ff:ff:ff:ff:ff:ff, ethertype ARP (0x0806), length 42: Ethernet (len 6), IPv4 (len 4), Request who-has 10.10.1.21 tell 10.10.1.251, length 28
02:20:25.717855 00:04:75:70:ab:06 > ff:ff:ff:ff:ff:ff, ethertype ARP (0x0806), length 42: Ethernet (len 6), IPv4 (len 4), Request who-has 10.10.1.21 tell 10.10.1.251, length 28
02:20:31.295167 00:04:75:70:ab:06 > ff:ff:ff:ff:ff:ff, ethertype ARP (0x0806), length 42: Ethernet (len 6), IPv4 (len 4), Request who-has 10.10.1.21 tell 10.10.1.251, length 28
^C
3 packets captured

fbsd# tcpdump -evvnpi xl0 host 10.10.1.21

tcpdump: listening on xl0, link-type EN10MB (Ethernet), capture size 65535 bytes

02:20:20.608069 00:04:75:70:ab:06 > ff:ff:ff:ff:ff:ff, ethertype ARP (0x0806), length 42: Ethernet (len 6), IPv4 (len 4), Request who-has 10.10.1.21 tell 10.10.1.251, length 28

02:20:25.717855 00:04:75:70:ab:06 > ff:ff:ff:ff:ff:ff, ethertype ARP (0x0806), length 42: Ethernet (len 6), IPv4 (len 4), Request who-has 10.10.1.21 tell 10.10.1.251, length 28

02:20:31.295167 00:04:75:70:ab:06 > ff:ff:ff:ff:ff:ff, ethertype ARP (0x0806), length 42: Ethernet (len 6), IPv4 (len 4), Request who-has 10.10.1.21 tell 10.10.1.251, length 28

3 packets captured

ARP Req также отправляется через xl0 уже без тега, происходит это на каждый входящий IP пакет, система видит что для ответного пакета с src 10.10.1.21 нужно отправлять данные через интерфейс xl0:

fbsd# route -n get 10.10.1.21
   route to: 10.10.1.21
destination: 10.10.1.0
       mask: 255.255.255.0
  interface: xl0
      flags: <UP,DONE>
 recvpipe  sendpipe  ssthresh  rtt,msec    mtu        weight    expire
       0         0         0         0      1500         1         0

fbsd# route -n get 10.10.1.21

route to: 10.10.1.21

destination: 10.10.1.0

mask: 255.255.255.0

interface: xl0

flags: <UP,DONE>

recvpipe sendpipe ssthresh rtt,msec mtu weight expire

0 0 0 0 1500 1 0

А так как нет ARP записи для адреса 10.10.1.21 через интерфейс xl0, мы отправляем ARP Req, а ICMP пакет дропаем.

ARP таблица для подсети 10.10.1.0

fbsd# arp -an | grep 10.10.1
? (10.10.1.21) at 00:0d:61:b0:8a:b1 on vlan18 expires in 991 seconds [vlan]
? (10.10.1.251) at 00:04:75:70:ab:06 on xl0 permanent [ethernet]

fbsd# arp -an | grep 10.10.1

? (10.10.1.21) at 00:0d:61:b0:8a:b1 on vlan18 expires in 991 seconds [vlan]

? (10.10.1.251) at 00:04:75:70:ab:06 on xl0 permanent [ethernet]

Мы можем явно добавить статическую запись через xl0:

fbsd# arp -s 10.10.1.21 00:0d:61:b0:8a:b1 xl0
fbsd# arp -n 10.10.1.21
? (10.10.1.21) at 00:0d:61:b0:8a:b1 on vlan18 expires in 862 seconds [vlan]
? (10.10.1.21) at 00:0d:61:b0:8a:b1 on xl0 permanent [ethernet]

fbsd# arp -s 10.10.1.21 00:0d:61:b0:8a:b1 xl0

fbsd# arp -n 10.10.1.21

? (10.10.1.21) at 00:0d:61:b0:8a:b1 on vlan18 expires in 862 seconds [vlan]

? (10.10.1.21) at 00:0d:61:b0:8a:b1 on xl0 permanent [ethernet]

Далее попробуем пропинговать

fbsd# tcpdump -evvnpi vlan18 host 10.10.1.21
tcpdump: listening on vlan18, link-type EN10MB (Ethernet), capture size 65535 bytes
01:56:01.663091 00:0d:61:b0:8a:b1 > 00:04:75:70:ab:06, ethertype IPv4 (0x0800), length 74: (tos 0x0, ttl 128, id 7023, offset 0, flags [none], proto ICMP (1), length 60)
10.10.1.21 > 10.10.1.251: ICMP echo request, id 512, seq 31744, length 40

fbsd# tcpdump -evvnpi vlan18 host 10.10.1.21

tcpdump: listening on vlan18, link-type EN10MB (Ethernet), capture size 65535 bytes

01:56:01.663091 00:0d:61:b0:8a:b1 > 00:04:75:70:ab:06, ethertype IPv4 (0x0800), length 74: (tos 0x0, ttl 128, id 7023, offset 0, flags [none], proto ICMP (1), length 60)

10.10.1.21 > 10.10.1.251: ICMP echo request, id 512, seq 31744, length 40

Исходящий (в никуда)

fbsd# tcpdump -evvnpi xl0 host 10.10.1.21
tcpdump: listening on xl0, link-type EN10MB (Ethernet), capture size 65535 bytes
02:26:01.663112 00:04:75:70:ab:06 > 00:0d:61:b0:8a:b1, ethertype IPv4 (0x0800), length 74: (tos 0x0, ttl 64, id 43486, offset 0, flags [none], proto ICMP (1), length 60)
10.10.1.251 > 10.10.1.21: ICMP echo reply, id 512, seq 31744, length 40

fbsd# tcpdump -evvnpi xl0 host 10.10.1.21

tcpdump: listening on xl0, link-type EN10MB (Ethernet), capture size 65535 bytes

02:26:01.663112 00:04:75:70:ab:06 > 00:0d:61:b0:8a:b1, ethertype IPv4 (0x0800), length 74: (tos 0x0, ttl 64, id 43486, offset 0, flags [none], proto ICMP (1), length 60)

10.10.1.251 > 10.10.1.21: ICMP echo reply, id 512, seq 31744, length 40

При такой конфигурации удалить ARP запись для «10.10.1.21» через интерфейсе VLAN18 не получится:

fbsd# arp -d 10.10.1.21
arp: writing to routing socket: Invalid argument

1 2	fbsd# arp -d 10.10.1.21 arp: writing to routing socket: Invalid argument

Решение:

fbsd# ifconfig xl0 -alias 10.10.1.251

1	fbsd# ifconfig xl0 -alias 10.10.1.251

fbsd# route -n get 10.10.1.21
   route to: 10.10.1.21
destination: 10.10.1.0
       mask: 255.255.255.0
  interface: vlan18
      flags: <UP,DONE>
 recvpipe  sendpipe  ssthresh  rtt,msec    mtu        weight    expire
       0         0         0         0      1500         1         0

fbsd# route -n get 10.10.1.21

route to: 10.10.1.21

destination: 10.10.1.0

mask: 255.255.255.0

interface: vlan18

flags: <UP,DONE>

recvpipe sendpipe ssthresh rtt,msec mtu weight expire

0 0 0 0 1500 1 0

И трафик пошел:

fbsd# tcpdump -evvnpi vlan18 host 10.10.1.21
tcpdump: listening on vlan18, link-type EN10MB (Ethernet), capture size 65535 bytes
02:33:22.353646 00:0d:61:b0:8a:b1 > 00:04:75:70:ab:06, ethertype IPv4 (0x0800), length 74: (tos 0x0, ttl 128, id 59143, offset 0, flags [none], proto ICMP (1), length 60)
10.10.1.21 > 10.10.1.251: ICMP echo request, id 512, seq 33024, length 40
02:33:22.353665 00:04:75:70:ab:06 > 00:0d:61:b0:8a:b1, ethertype IPv4 (0x0800), length 74: (tos 0x0, ttl 64, id 4902, offset 0, flags [none], proto ICMP (1), length 60)
10.10.1.251 > 10.10.1.21: ICMP echo reply, id 512, seq 33024, length 40

fbsd# tcpdump -evvnpi vlan18 host 10.10.1.21

tcpdump: listening on vlan18, link-type EN10MB (Ethernet), capture size 65535 bytes

02:33:22.353646 00:0d:61:b0:8a:b1 > 00:04:75:70:ab:06, ethertype IPv4 (0x0800), length 74: (tos 0x0, ttl 128, id 59143, offset 0, flags [none], proto ICMP (1), length 60)

10.10.1.21 > 10.10.1.251: ICMP echo request, id 512, seq 33024, length 40

02:33:22.353665 00:04:75:70:ab:06 > 00:0d:61:b0:8a:b1, ethertype IPv4 (0x0800), length 74: (tos 0x0, ttl 64, id 4902, offset 0, flags [none], proto ICMP (1), length 60)

10.10.1.251 > 10.10.1.21: ICMP echo reply, id 512, seq 33024, length 40

Интерфейс для маршрутизации выбирается на основе «1-ой включенной подсети»:

fbsd# ifconfig xl0 | grep inet
        inet 10.55.5.51 netmask 0xffffff00 broadcast 10.55.5.255
fbsd# ifconfig vlan18 | grep inet
        inet 10.10.1.251 netmask 0xffffff00 broadcast 10.10.1.255

fbsd# ifconfig xl0 | grep inet

inet 10.55.5.51 netmask 0xffffff00 broadcast 10.55.5.255

fbsd# ifconfig vlan18 | grep inet

inet 10.10.1.251 netmask 0xffffff00 broadcast 10.10.1.255

fbsd# ifconfig xl0 alias 10.10.1.251/24 up
fbsd# route -n get 10.10.1.21
   route to: 10.10.1.21
destination: 10.10.1.0
       mask: 255.255.255.0
  interface: vlan18
      flags: <UP,DONE>
 recvpipe  sendpipe  ssthresh  rtt,msec    mtu        weight    expire
       0         0         0         0      1500         1         0

fbsd# ifconfig xl0 alias 10.10.1.251/24 up

fbsd# route -n get 10.10.1.21

route to: 10.10.1.21

destination: 10.10.1.0

mask: 255.255.255.0

interface: vlan18

flags: <UP,DONE>

recvpipe sendpipe ssthresh rtt,msec mtu weight expire

0 0 0 0 1500 1 0

IPv5

Архив за месяц: Октябрь 2016

Linux 2 ISP и ARP

ARP и одинаковые подсети

Networking