上回說到設置共享文件夾需要關閉防火牆：
service iptables stop 或 systemctl stop firewalld
但是由於網絡安全的問題，我們需要保持防火牆開啟，如此便引入了新的問題：
打開防火牆后，會產生報錯信息：
clnt_create: RPC: Port mapper failure - Unable to receive: errno 113 (No route to host)
rpc mount export: RPC: Unable to receive; errno = No route to host
該報錯是因為我們將nfs的端口也禁用了，需要開啟。
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找了很多辦法，都比較亂，最終還是解決了。
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首先，查看端口情況
rpcinfo -p
program vers proto port service
100000 4 tcp 111 portmapper
100000 3 tcp 111 portmapper
100000 2 tcp 111 portmapper
100000 4 udp 111 portmapper
100000 3 udp 111 portmapper
100000 2 udp 111 portmapper
100024 1 udp 39351 status
100024 1 tcp 52381 status
100021 1 udp 51619 nlockmgr
100021 3 udp 51619 nlockmgr
100021 4 udp 51619 nlockmgr
打開防火牆，查看當前共享情況
showmount -e 192.168.
clnt_create: RPC: Port mapper failure - Unable to receive: errno 113 (No route to host)
編輯文檔，加入如下信息（主要是打開portmapper、mountd、nfs三個端口）
/etc/sysconfig/iptables
-A INPUT -p tcp -m state --state NEW -m tcp --dport 2049 -j ACCEPT
-A INPUT -m state --state NEW -m udp -p udp --dport 2049 -j ACCEPT
-A INPUT -p tcp -m state --state NEW -m tcp --dport 111 -j ACCEPT
-A INPUT -m state --state NEW -m udp -p udp --dport 111 -j ACCEPT
-A INPUT -p tcp -m state --state NEW -m tcp --dport 20048 -j ACCEPT
-A INPUT -m state --state NEW -m udp -p udp --dport 20048 -j ACCEPT
若顯示如下：則需安裝iptables-services：（yum install iptables-services systemctl enable iptables.service）
iptables -L -n
Chain INPUT (policy ACCEPT)
target prot opt source destination
ACCEPT udp -- 0.0.0.0/0 0.0.0.0/0 udp dpt:53
ACCEPT tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt:53
ACCEPT udp -- 0.0.0.0/0 0.0.0.0/0 udp dpt:67
ACCEPT tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt:67
ACCEPT all -- 0.0.0.0/0 0.0.0.0/0 ctstate RELATED,ESTABLISHED
ACCEPT all -- 0.0.0.0/0 0.0.0.0/0
INPUT_direct all -- 0.0.0.0/0 0.0.0.0/0
INPUT_ZONES_SOURCE all -- 0.0.0.0/0 0.0.0.0/0
INPUT_ZONES all -- 0.0.0.0/0 0.0.0.0/0
DROP all -- 0.0.0.0/0 0.0.0.0/0 ctstate INVALID
REJECT all -- 0.0.0.0/0 0.0.0.0/0 reject-with icmp-host-prohibited
ACCEPT tcp -- 0.0.0.0/0 0.0.0.0/0 state NEW tcp dpt:2049
Chain FORWARD (policy ACCEPT)
target prot opt source destination
ACCEPT all -- 0.0.0.0/0 192.168.122.0/24 ctstate RELATED,ESTABLISHED
ACCEPT all -- 192.168.122.0/24 0.0.0.0/0
ACCEPT all -- 0.0.0.0/0 0.0.0.0/0
REJECT all -- 0.0.0.0/0 0.0.0.0/0 reject-with icmp-port-unreachable
REJECT all -- 0.0.0.0/0 0.0.0.0/0 reject-with icmp-port-unreachable
ACCEPT all -- 0.0.0.0/0 0.0.0.0/0 ctstate RELATED,ESTABLISHED
ACCEPT all -- 0.0.0.0/0 0.0.0.0/0
FORWARD_direct all -- 0.0.0.0/0 0.0.0.0/0
FORWARD_IN_ZONES_SOURCE all -- 0.0.0.0/0 0.0.0.0/0
FORWARD_IN_ZONES all -- 0.0.0.0/0 0.0.0.0/0
FORWARD_OUT_ZONES_SOURCE all -- 0.0.0.0/0 0.0.0.0/0
FORWARD_OUT_ZONES all -- 0.0.0.0/0 0.0.0.0/0
DROP all -- 0.0.0.0/0 0.0.0.0/0 ctstate INVALID
REJECT all -- 0.0.0.0/0 0.0.0.0/0 reject-with icmp-host-prohibited
Chain OUTPUT (policy ACCEPT)
target prot opt source destination
ACCEPT udp -- 0.0.0.0/0 0.0.0.0/0 udp dpt:68
ACCEPT all -- 0.0.0.0/0 0.0.0.0/0
OUTPUT_direct all -- 0.0.0.0/0 0.0.0.0/0
Chain FORWARD_IN_ZONES (1 references)
target prot opt source destination
FWDI_public all -- 0.0.0.0/0 0.0.0.0/0 [goto]
FWDI_public all -- 0.0.0.0/0 0.0.0.0/0 [goto]
Chain FORWARD_IN_ZONES_SOURCE (1 references)
target prot opt source destination
Chain FORWARD_OUT_ZONES (1 references)
target prot opt source destination
FWDO_public all -- 0.0.0.0/0 0.0.0.0/0 [goto]
FWDO_public all -- 0.0.0.0/0 0.0.0.0/0 [goto]
Chain FORWARD_OUT_ZONES_SOURCE (1 references)
target prot opt source destination