Êîìàíäà IP â Linux: ðóêîâîäñòâî ñ ïðèìåðàìè

Êîìàíäà ip - ýòî ñåòåâîé èíñòðóìåíò Linux äëÿ ñèñòåìíûõ è ñåòåâûõ àäìèíèñòðàòîðîâ. IP îçíà÷àåò Èíòåðíåò-ïðîòîêîë è, êàê ñëåäóåò èç íàçâàíèÿ, èíñòðóìåíò èñïîëüçóåòñÿ äëÿ íàñòðîéêè ñåòåâûõ èíòåðôåéñîâ.  ñòàðûõ äèñòðèáóòèâàõ Linux èñïîëüçîâàëàñü êîìàíäà ifconfig, êîòîðàÿ ðàáîòàåò àíàëîãè÷íî. Îäíàêî ifconfig èìååò îãðàíè÷åííûé äèàïàçîí âîçìîæíîñòåé ïî ñðàâíåíèþ ñ êîìàíäîé ip.

 ýòîì ðóêîâîäñòâå ìû ðàññìîòðèì âñå âàæíûå îïåðàöèè, êîòîðûå êîìàíäà ip ìîæåò âûïîëíÿòü â Linux.

Êàê èñïîëüçîâàòü êîìàíäó ip

Êîìàíäà ip èìååò ñëåäóþùèé ñèíòàêñèñ:

ip [OPTION] OBJECT {COMMAND | help}

Ê îáúåêòàì OBJECT (èëè ïîäêîìàíäàì), êîòîðûå âû áóäåòå èñïîëüçîâàòü ÷àùå âñåãî, îòíîñÿòñÿ:

1. link (l) - èñïîëüçóåòñÿ äëÿ îòîáðàæåíèÿ è èçìåíåíèÿ ñåòåâûõ èíòåðôåéñîâ
2. address (addr/a) - èñïîëüçóåòñÿ äëÿ îòîáðàæåíèÿ è èçìåíåíèÿ àäðåñîâ ïðîòîêîëà (IP, IPv6)
3. route (r) - èñïîëüçóåòñÿ äëÿ îòîáðàæåíèÿ è èçìåíåíèÿ òàáëèöû ìàðøðóòèçàöèè
4. neigh (n) - èñïîëüçóåòñÿ äëÿ îòîáðàæåíèÿ è óïðàâëåíèÿ ñîñåäíèìè îáúåêòàìè (òàáëèöà ARP)

Îíè ìîãóò èñïîëüçîâàòüñÿ êàê â ïîëíîé, òàê è ñîêðàùåííîé ôîðìå.

Åñòü ìíîãî äðóãèõ äîñòóïíûõ îáúåêòîâ è êîìàíä. ×òîáû óâèäåòü ïîëíûé ñïèñîê, ââåäèòå ñëåäóþùóþ êîìàíäó:

ip help

Äëÿ âûïîëíåíèÿ êîìàíä âû ìîæåòå èñïîëüçîâàòü ëèáî ïîëíóþ, ëèáî ñîêðàùåííóþ ôîðìû. Íàïðèìåð, ip link è ip l áóäóò äàâàòü îäèíàêîâûå ðåçóëüòàòû.

Ïðè íàñòðîéêå ñåòåâûõ èíòåðôåéñîâ âû äîëæíû çàïóñêàòü êîìàíäû êàê ïîëüçîâàòåëü root èëè ïîëüçîâàòåëü ñ ïðèâèëåãèÿìè sudo.  ïðîòèâíîì ñëó÷àå âû óâèäèòå ñîîáùåíèå RTNETLINK answers: Operation not permitted

Ïðåäóïðåæäåíèå: ïî óìîë÷àíèþ ñèñòåìà íå ñîõðàíÿåò èçìåíåíèÿ ïåðìàíåíòíî. Ïîñëå ïåðåçàïóñêà Linux-ñåðâåðà âíîâü èçìåíåííîå ñîñòîÿíèå áóäåò ïîòåðÿíî. Åñòü äâà ñïîñîáà ñäåëàòü âàøè íàñòðîéêè ïîñòîÿííûìè: äîáàâèòü êîìàíäû â ñöåíàðèé çàïóñêà èëè îòðåäàêòèðîâàòü äèñòðèáóòèâíûå ôàéëû êîíôèãóðàöèè.

Óïðàâëåíèå è îòîáðàæåíèå ñåòåâûõ èíòåðôåéñîâ

Âû ìîæåòå ïîëó÷èòü ñïèñîê âñåõ ïàðàìåòðîâ êîìàíäû link, íàáðàâ:

ip link help

Ïîëó÷èòü èíôîðìàöèþ î ñåòåâîì èíòåðôåéñå

×òîáû óâèäåòü èíôîðìàöèþ êàíàëüíîãî óðîâíÿ îáî âñåõ äîñòóïíûõ óñòðîéñòâàõ (ó êîòîðûõ çàãðóæåí äðàéâåð), èñïîëüçóéòå êîìàíäó:

ip link show

Ïðèìåð âûâîäà:

1: lo:  mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: eth0:  mtu 1500 qdisc fq_codel state UP mode DEFAULT group default qlen 1000
    link/ether 12:24:01:8c:67:45 brd ff:ff:ff:ff:ff:ff

Åñëè âû õîòèòå, ÷òîáû êîìàíäà îòîáðàæàëà èíôîðìàöèþ äëÿ îäíîãî êîíêðåòíîãî óñòðîéñòâà, ââåäèòå ñëåäóþùåå:

ip link show dev [device]

×òîáû ïðîñìîòðåòü ñòàòèñòèêó ïî âñåì ñåòåâûì èíòåðôåéñàì (òàêèå äåòàëè, êàê ïåðåäàííûå èëè îòáðîøåííûå ïàêåòû èëè äàæå îøèáêè), èñïîëüçóéòå:

ip -s link

Âû òàêæå ìîæåòå óâèäåòü àíàëîãè÷íóþ èíôîðìàöèþ äëÿ îòäåëüíîãî ñåòåâîãî èíòåðôåéñà:

ip -s link ls [interface]

Åñëè âàì íóæíî áîëüøå ïîäðîáíîñòåé, äîáàâüòå åùå -s â ñèíòàêñèñ:

ip -s -s link ls [interface]

×òîáû óâèäåòü ñïèñîê òîëüêî ðàáîòàþùèõ èíòåðôåéñîâ, èñïîëüçóéòå:

ip link ls up

Èçìåíèòü ñòàòóñ ñåòåâîãî èíòåðôåéñà

Åñëè âû õîòèòå âêëþ÷èòü ñåòåâîé èíòåðôåéñ, èñïîëüçóéòå êîìàíäó:

ip link set [interface] up

Îòêëþ÷èòå èíòåðôåéñ, ââåäÿ:

ip link set [interface] down

Êîìàíäà ip link ïîçâîëÿåò âàì èçìåíÿòü î÷åðåäü ïåðåäà÷è, óñêîðÿÿ èëè çàìåäëÿÿ èíòåðôåéñû â ñîîòâåòñòâèè ñ âàøèìè ïîòðåáíîñòÿìè è àïïàðàòíûìè âîçìîæíîñòÿìè.

ip link set txqueuelen [number] dev [interface]

Âû ìîæåòå óñòàíîâèòü MTU (Maximum Transmission Unit) äëÿ óëó÷øåíèÿ ïðîèçâîäèòåëüíîñòè ñåòè:

ip link set mtu [number] dev [interface]

×òîáû óçíàòü âñå îïöèè êîìàíäû link, íàáåðèòå:

ip link help

Ìîíèòîðèíã è óïðàâëåíèå IP-àäðåñàìè

Óçíàéòå âñå êîìàíäû address, íàáðàâ ñëåäóþùåå:

ip addr help

Ìîíèòîðèíã IP-àäðåñîâ

Âûâåäèòå âñå óñòðîéñòâà ñ ïîìîùüþ ñëåäóþùåé êîìàíäû:

ip addr

×òîáû âûâåñòè ñïèñîê âñåõ ñåòåâûõ èíòåðôåéñîâ è ñâÿçàííûõ IP-àäðåñîâ, èñïîëüçóéòå êîìàíäó:

ip addr show

Ïðèìåð âûâîäà:

1: lo:  mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
2: eth0:  mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 51:55:07:8a:62:44 brd ff:ff:ff:ff:ff:ff
    inet 192.168.120.24/24 brd 192.168.120.255 scope global dynamic eth0
       valid_lft 2900sec preferred_lft 2900sec
    inet6 fe80::5054:ff:fe8c:6244/64 scope link 
       valid_lft forever preferred_lft forever

Âû òàêæå ìîæåòå óâèäåòü èíôîðìàöèþ îá îòäåëüíîé ñåòè:

ip addr show dev [interface]

×òîáû ïîëó÷èòü ñïèñîê âñåõ IPv4 àäðåñîâ, èñïîëüçóéòå:

ip -4 addr

×òîáû ïîëó÷èòü ñïèñîê âñåõ IPv6 àäðåñîâ, èñïîëüçóéòå:

ip -6 addr

Êàê äîáàâèòü IP-àäðåñ â Linux

Äîáàâüòå IP-àäðåñ â èíòåðôåéñ ñ ïîìîùüþ êîìàíäû:

ip addr add [ip_address] dev [interface]

Åñëè óêàçàííûé èíòåðôåéñ íå ñóùåñòâóåò, îòîáðàçèòñÿ ñîîáùåíèå: Cannot find device [interface]

×òîáû äîáàâèòü äâà àäðåñà íà îäèí èíòåðôåéñ òàêæå èñïîëüçóéòå ýòó êîìàíäó:

ip address add 192.168.1.41/24 dev eth0
ip address add 192.168.1.40/24 dev eth0

Åñëè âàì íóæíî äîáàâèòü øèðîêîâåùàòåëüíûé (broadcast) àäðåñ äëÿ èíòåðôåéñà, èñïîëüçóéòå êîìàíäó:

ip addr add brd [ip_address] dev [interface]

×òîáû óäàëèòü IP-àäðåñ èç èíòåðôåéñà, âûïîëíèòå ñëåäóþùèå äåéñòâèÿ.

ip addr del [ip_address] dev [interface]

Óïðàâëåíèå è îòîáðàæåíèå òàáëèöû IP-ìàðøðóòèçàöèè

Ïðîñìîòðèòå ïîëíûé ñïèñîê êîìàíä ip routeñ ïîìîùüþ ñëåäóþùåé êîìàíäû:

ip route help

Ïîêàçàòü òàáëèöó ìàðøðóòèçàöèè IP

Äëÿ ïðîñìîòðà âñåõ çàïèñåé â òàáëèöå ìàðøðóòèçàöèè èñïîëüçóéòå îäíó èç ñëåäóþùèõ êîìàíä:

ip route

ip route list

Ïðèìåð âûâîäà:

default via 192.168.1.1 dev eth0 proto dhcp src 192.168.1.241 metric 100 
192.168.1.0/24 dev eth0 proto kernel scope link src 192.168.1.241 
192.168.1.1 dev eth0 proto dhcp scope link src 192.168.1.241 metric 100 

Ñ ïîìîùüþ êîìàíä, ïðèâåäåííûõ âûøå, âûõîäíûå äàííûå îòîáðàæàþò âñå çàïèñè ìàðøðóòà â ÿäðå. Åñëè âàì íóæíî ñóçèòü ïîèñê, äîáàâüòå îáúåêò SELECTOR:

ip route list SELECTOR

×òîáû ïðîñìîòðåòü ìàðøðóòèçàöèþ äëÿ îòäåëüíîé ñåòè, èñïîëüçóéòå ñëåäóþùèé ñèíòàêñèñ:

ip route list [ip_address]

Èçìåíèòü òàáëèöó IP-ìàðøðóòèçàöèè

×òîáû äîáàâèòü íîâóþ çàïèñü â òàáëèöó ìàðøðóòèçàöèè, ââåäèòå êîìàíäó:

ip route add [ip_address] dev [interface]

Èëè âû ìîæåòå äîáàâèòü íîâûé ìàðøðóò ÷åðåç øëþç, íàáðàâ:

ip route add [ip_address] via [gateway_IP]

Òàêæå êîìàíäà ïîçâîëÿåò äîáàâèòü ìàðøðóò äëÿ âñåõ àäðåñîâ ÷åðåç ëîêàëüíûé øëþç, äîáàâèâ ïàðàìåòð default:

ip route add default [ip_address] dev [device]

ip route add default [network/mask] via [gateway_IP]

×òîáû óäàëèòü ñóùåñòâóþùóþ çàïèñü â òàáëèöå ìàðøðóòèçàöèè, èñïîëüçóéòå êîìàíäû:

ip route del [ip_address]

ip route del default

ip route del [ip_address] dev [interface]

Îòîáðàæåíèå è èçìåíåíèå IP-çàïèñåé ñîñåäåé

Ïðè ïîìîùè êîìàíäû ip neigh ìîæíî ìàíèïóëèðîâàòü òàáëèöàìè ARP (Address Resolution Protocol). Ýòî àíàëîã êîìàíäû arp

Äëÿ ïîëó÷åíèÿ ïîëíîãî ñïèñêà âñåõ ïàðàìåòðîâ êîìàíäû neigh èñïîëüçóéòå:

ip neigh help

Îòîáðàæåíèå IP-àäðåñîâ ñîñåäåé

×òîáû îòîáðàçèòü òàáëèöû ñîñåäåé, èñïîëüçóéòå ñëåäóþùóþ êîìàíäó:

ip neigh show

Âûõîäíûå äàííûå ïîêàçûâàþò MAC-àäðåñà óñòðîéñòâ, êîòîðûå ÿâëÿþòñÿ ÷àñòüþ ñèñòåìû, è èõ ñîñòîÿíèå. Ñîñòîÿíèå óñòðîéñòâà ìîæåò áûòü:

• REACHABLE - îçíà÷àåò âàëèäíóþ, äîñòèæèìóþ çàïèñü äî èñòå÷åíèÿ òàéìàóòà.
• PERMANENT - îçíà÷àåò ïîñòîÿííóþ çàïèñü, êîòîðóþ ìîæåò óäàëèòü òîëüêî àäìèíèñòðàòîð
• STALE - îçíà÷àåò äåéñòâèòåëüíóþ, íî íåäîñòóïíóþ çàïèñü
• DELAY - îçíà÷àåò, ÷òî ÿäðî âñå åùå îæèäàåò ïðîâåðêè èç óñòàðåâøåé çàïèñè

Èçìåíèòü IP-çàïèñè ñîñåäåé

Äîáàâüòå íîâóþ çàïèñü â òàáëèöó ñ ïîìîùüþ êîìàíäû:

ip neigh add [ip_address] dev [interface]

Èëè óäàëèòå ñóùåñòâóþùóþ çàïèñü ARP:

ip neigh del [ip_address] dev [interface]