The 48-year-old was dismissed from her pound;35,000 a year position as head of food technology at New Park special school, in Salford, after a five-hour disciplinary hearing. She is to appeal against the decision to sack her, made by the Labour-controlled council in Salford.
Mrs Walker still faces an inquiry by the Department for Education and Skills which could be referred to England's General Teaching Council.
Tim Barnes, head of Mesne Lea primary, said: "What she did was incorrect and wrong. But it was a matter wholly unrelated to her work. I don't think it reflects on her ability to do her job. If she was a teacher at my school, I wouldn't have any qualms about telling my governors that she should remain in the job."
Richard Healey, a teacher at St Andrew's Church of England primary, said:
"The word in the staffroom is that the decision was too harsh. Most people were outraged. A lot of teachers have issues with teenagers targeting their houses because of their position at school."
Mrs Walker, a teacher with 25 years' experience, was found guilty by a Manchester crown court of affray and possessing a firearm with intent to cause fear. In April, she was sentenced to six months in jail.
She said she had fired the airgun at the teenagers because they had been harassing her family and vandalising her garden.
She served 36 days of the sentence, before appeal judges reversed the sentence, and she was released on May 4.
It is understood that council representatives told the disciplinary hearing that her criminal conviction has rendered her unfit to work as a teacher.
But many Salford teachers say she should resume her career.
Garry Schofield, head of Charlestown primary, said: "She was sent to prison. I would question the decision to give her a double punishment. It's not like she's done anything wrong in her professional life. I would be happy to have her teach at my school."
But Daryl Richardson, deputy head at Hope high, said: "Most people are sympathetic, but the law is the law. Firing a gun is a serious crime. Those teenagers clearly caused her a lot of stress. But in the classroom you need to be able to manage stress appropriately. The safety of our pupils has to be our number-one concern."
Teachers on The TES online staffroom have also backed Mrs Walker. One said:
"Linda, what has happened to you is the most sickening of injustices. The system has failed you." Other contributors called for teachers to go on strike until the decision was reversed and said staff should have a "whip-round" for her.
Mrs Walker will not comment on the authority's decision until her appeal has been heard.
Staff at New Park were unwilling to comment, and a spokesman for Salford council said the details of the hearing were confidential. But he added:
"This case has been progressed in accordance with formal city council procedures."
Chris Keates, general secretary of NASUWT, her union, said the dismissal was highly regrettable. "This decision adds to the deep trauma and distress that she has already suffered," she said.