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A write operation error

‎03-29-2020 03:24 PM

hi,

There are errors on mx below... why those cases are happening and what troubleshooting and resolution can be done?

1-)DCD_CONFIG_WRITE_FAILED: IFA em0.0 (family=2) configuration write failed for an IFA ADD: Can't assign requested address

2-) SNMPD_AUTH_FAILURE: nsa_log_community: unauthorized SNMP community from 192.168.15.10 192.168.25.10 (public)

 

Thx

A

21 REPLIES 21
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Re: A write operation error

[ Edited ]
‎03-29-2020 06:38 PM

Hi ,

1) show us configuration of em0 interface (and show version)

2) somebody is trying to send snmp query from 192.168.15.10 to you MX, but this addtess does not configured in 

          set snmp community XXXX clients 192.168.15.10

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Re: A write operation error

‎03-29-2020 07:55 PM

ver: 17.3R3.1. Only a few statements here:
set interfaces em0 unit 0 family inet address 10.10.10.1/24
set interfaces em1 unit 0 family inet address 10.10.20.1/24

set interfaces em2 unit 0 family inet address 10.10.30.1/24

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Re: A write operation error

‎03-29-2020 08:21 PM

check if em0 is present in system (show interface em0)

check is any other interface on this router configured with address in net 10.10.10.0/24 (show route 10.10.10.0/24)

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Re: A write operation error

‎03-29-2020 09:23 PM

Yes those -em0 and em1 are being presented...Traffic on em0 is high than em1. em2 is not presented.

 

Spoiler
>set statements
set interfaces em0 unit 0 family inet address 10.10.10.1/24
set interfaces em1 unit 0 family inet address 10.10.10.2/24
set interfaces em2 unit 0 family inet address 10.10.10.3/24

>sh route
10.10.10.0/24      *[Direct/0] 33w5d 44:18:52
                    > via em1.0
10.10.10.2/32      *[Local/0] 33w5d 44:18:52
                      Local via em1.0
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Re: A write operation error

‎03-29-2020 10:29 PM

Your em interface addresses don't match what you have up above, and are in the same subnet--which is probably the source of your issue.

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Re: A write operation error

‎03-29-2020 11:09 PM

You should not assign addresses from same subnet to different interfaces within same routing table. 

 

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Re: A write operation error

‎03-30-2020 01:21 AM

 

Just trying to understand the case based on point of your viewes but when looking at the syslog database, it says the following:

 

>help sys DCD_CONFIG_WRITE_FAILED
Name: DCD_CONFIG_WRITE_FAILED
Message: <interface-name> configuration write failed for an <object-name> <operation>: <error-message>
Help: DCD configuration write failed
Description: DCD encountered an error while trying to send an interface configuration to the kernel over the routing socket.
Type: Internal: Internal log message
Severity: error
Facility: LOG_DAEMON
Cause: A write operation over the routing socket returned a bad status.
Action: Contact your technical support representative.

is it the same thing or?

 

thx

A

 

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Re: A write operation error

‎03-30-2020 01:27 AM

Yes, it is the same

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Re: A write operation error

‎03-30-2020 06:26 AM

any idea, how can we fix this?

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Re: A write operation error

‎03-31-2020 03:20 PM

Any replies pls?

 

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Re: A write operation error

‎04-01-2020 02:49 AM

Hi,

please provide in one go:

1. show system information

2. show configuration interfaces em0 / em1 / em2 | display inheritance

3. show interfaces em* brief

Regards

Ulf

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Re: A write operation error

‎04-01-2020 05:43 AM
> show system information
Model: mx104
Family: junos
Junos: 17.3R3.1

>show configuration interfaces em0 | display inheritance
unit 0 {
family inet {
address 10.10.10.1/24;
}
}
> show configuration interfaces em1 | display inheritance
unit 0 {
family inet {
address 10.10.10.2/24;
}
}
> show configuration interfaces em2 | display inheritance ---->nothing anything.don't worry.
.......

>show interfaces em* brief
Physical interface: em0, Enabled, Physical link is Up
Type: Ethernet, Link-level type: Ethernet, MTU: 1514, Clocking: Unspecified, Speed: Unspecified
Device flags : Present Running
Interface flags: SNMP-Traps
Logical interface em0.0
Flags: Up SNMP-Traps 0x0 Encapsulation: ENET2
inet 10.0.0.4/8
128.0.0.1/2
128.0.0.4/2
inet6 fe80::100:fe:fe00:4/64
fec0::a:0:0:4/64
tnp 0x4
Physical interface: em1, Enabled, Physical link is Up Type: Ethernet, Link-level type: Ethernet, MTU: 1514, Clocking: Unspecified, Speed: Unspecified Device flags : Present Running Interface flags: SNMP-Traps Logical interface em1.0 Flags: Up SNMP-Traps 0x0 Encapsulation: ENET2 inet 10.10.10.2/24 >show route 10.10.10.0/24 inet.0: 104596 destinations, 218799 routes (90657 active, 0 holddown, 14048 hidden) + = Active Route, - = Last Active, * = Both 10.10.10.0/24 *[Direct/0] 3w3d 22:42:59 > via em1.0 10.10.10.2/32 *[Local/0] 3w3d 22:42:59 Local via em1.0
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Re: A write operation error

‎04-01-2020 06:52 AM

Hi,

1. em0 and em1 seem to be internal interfaces on an MX104 and are not meant to be configured by the user / operator, they are surely neither revenue nor oob-mgmt-interfaces

2. why do you configure the same subnet on two different interfaces to start with?

Regards

Ulf

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Re: A write operation error

‎04-01-2020 01:54 PM

When looking at when those occurred on em0 and em1 on the box, couldn't find any related particular thing historically, so no idea...

 

What solutions should be to overcome with issue -IFA ADD?

 

Secondly how to determine about where these internal em0&1 are physically connected?

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Re: A write operation error

‎04-01-2020 11:48 PM

-> em0 and em1 are internal interfaces on an MX104 and are not meant to be used or configured by the user / operator!

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Re: A write operation error

‎04-02-2020 01:33 AM

hi Ulf,

Thanks for the reply...

I understood that you pointed "em0 and em1 are internal interfaces on an MX104 and are not meant to be used or configured by the user / operator!" If these interfaces are internal, what purpose or what reason Juniper Engineers did design those...If there is no reason(s), it just makes complicate mx devices.... 

 

Anyway......

.

I am still seeking for a solution(s).

Can I ask again what is solution(s)? Solution must be shutdown or delete both internal interfaces or. If so, what risk or impact can be seen on the box?

 

CAn I ask others any a proper solutions?

 

thx

A

 

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Re: A write operation error

‎04-02-2020 01:40 AM

Hi,

wrt to "If these interfaces are internal, what purpose or what reason Juniper Engineers did design those...If there is no reason(s), it just makes complicate mx devices.... " These interfaces are used for communication of the REs with other components in the chassis. So these are needed, but must not be configured or disabled! We can debate whether it's a good idea that these are exposed, but atm it is what it is.

Regards

Ulf

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Re: A write operation error

‎04-03-2020 04:59 AM

Hi Ulf,

Thanks for the answer,

 

Can I ask what default configuration of the internal interfaces -emx have when we purches the Mx?

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Re: A write operation error

‎04-03-2020 05:48 AM

They are configured internally as needed, which is intentionally not reflected in the config visible by "show configuration". So please don't configure them at all and they can work as they should.  Ulf

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